March LA.B Mansart: what does its owner think?

The March LA.B Mansart, unveiled at Baselworld in 2019, is an octagonal shaped watch that translates the geometry of Paris’s Place Vendôme, designed by Jules Hardouin-Mansart, into wristwatch form. Its approximately 34 mm-wide by 39 mm-long case moves away from a conventional round silhouette while retaining exceptionally restrained dimensions. The original automatic generation used the Japanese Miyota 90S5, without a date and with approximately 42 hours of power reserve; the collection subsequently evolved substantially through the adoption of the Swiss La Joux-Perret G100, assembled in Besançon, France, and offering 68 hours of autonomy, followed by the 35 x 39 mm Mansart Small Seconds and its La Joux-Perret G121 in 2025. Alongside these models, quartz-powered “Electric” versions retain the same shape in a thinner configuration. By 2026 Mansart has become a genuine family within March LA.B, extending from automatic date watches to small seconds, quartz pieces and several smaller women’s formats.

Design & legibility: the architecture of Place Vendôme on the wrist

Mansart is first and foremost a watch built around shape. Its case is neither simply square, rectangular nor round: it layers multiple octagonal planes whose surfaces alternate between polished and brushed finishing. March LA.B directly acknowledges Place Vendôme and Jules Hardouin-Mansart, architect to Louis XIV, as its inspiration. Octagonal geometry is the true distinguishing signature of the Mansart. Even without seeing the logo, the sequence of facets, offset crown and visual integration of the strap give it a silhouette that stands apart from most contemporary shaped watches.

The construction deliberately plays with light. Different layers of the case are not treated as one continuous surface: some areas are brushed, others polished, and each change of angle creates a different reflection as the wrist moves. This architecture gives a 34 or 35 mm watch considerably more visual presence than its size would normally suggest. Mansart creates presence through its facets rather than through diameter. This is particularly appealing for someone wanting a compact dress watch without allowing it to disappear visually on the wrist.

The crown is positioned around 4 o’clock and itself adopts a carefully worked geometric form. Its placement frees the right side of the case and prevents a conventional 3 o’clock crown from disturbing the symmetry of the overall shape. It also continues the slightly unconventional design language that March LA.B has used across several collections. The 4 o’clock crown forms part of the design rather than functioning merely as a setting control. Its dimensions remain restrained enough to avoid discomfort despite the pronounced angles of the case.

The dials follow the same architectural logic. Grall versions use the green closely associated with March LA.B, while White provides a more classical and brighter presentation. Recent generations use sandblasted or guilloché surfaces, exceptionally slender baton markers and an applied “M” logo that avoids excessive dial text. The dial is intentionally restrained so that the geometry of the case has space to breathe. Mansart has never attempted to accumulate numerals, scales or technical wording; it remains fundamentally an urban dress watch in which form has priority over information density.

On current automatic date versions, the aperture sits at 3 o’clock inside a metal frame echoing the angular lines of the watch. March LA.B introduces a small graphic detail through the calendar: on selected configurations, the numeral 3 appears in green on the third day of each month. The customised date display illustrates how the brand introduces playful details without disturbing the general balance. The date also provides one of the clearest distinctions between the G100 generation and the much more stripped-back automatic Mansart watches of 2019.

Mansart Small Seconds, introduced in 2025, changes the dial more substantially. Horizontal guilloché is paired with an offset seconds counter whose own octagonal geometry prevents it from looking like a complication simply placed on top of an existing design. Grall and Shelter use green and white registers respectively, while Golden Hour adopts a much more assertive gold treatment. The small seconds extends the case geometry directly into the organisation of the dial. It is probably the version that most completely develops the architectural concept established in 2019.

Case, bracelets and comfort: small dimensions with a strong identity

The current Mansart Automatic Date uses a 316L stainless-steel case measuring 34 x 39 mm. March LA.B states approximately 11 mm in its general technical specification, while detailed case information refers to approximately 10.2 mm depending on the measurement method. Weight is around 55 grams on leather and 100 grams on steel. The 34 mm width should not be interpreted like the diameter of a conventional small round watch. The octagonal outline, facets and 39 mm overall length create considerably more presence than the width alone suggests.

Mansart Small Seconds slightly expands the formula to 35 x 39 mm and approximately 11.1 mm thick. The increase in width is minimal, but the more complex dial and seconds counter make the watch appear visually busier. Weight is approximately 59 grams on leather and 104 grams on the steel bracelet. The move from 34 to 35 mm primarily accommodates the new display rather than representing a genuine attempt to enlarge Mansart. The historically compact character of the family therefore remains intact.

Electric versions pursue thinness much further. The case retains 34 x 39 mm dimensions but falls to approximately 8 mm thick thanks to the Ronda 1063 quartz calibre. Stated weight is approximately 48 grams on leather and 87 grams on steel. Mansart Electric is the version that expresses the slim octagonal case most purely. It makes particular sense for someone wanting a discreet shaped watch under a cuff and regarding mechanical movement as a secondary consideration.

Current models use antireflective sapphire positioned close to the upper surface of the case in order to maintain a visually monolithic profile. The first automatic Mansart watches already used slightly raised sapphire to provide depth without creating a strongly domed vintage effect. Sapphire protects a design intended more for urban life than intensive sporting use. Its scratch resistance is especially appropriate for a dress-oriented watch likely to be worn frequently.

Water resistance is rated at 5 ATM, or 50 metres, across current automatic, Small Seconds and Electric Mansart watches. This provides useful protection against rain and accidental splashes but clearly does not turn the model into an aquatic watch. Alligator and lizard straps reinforce that dress-oriented purpose. Mansart should be regarded as an urban watch protected against normal everyday accidents rather than as a sports watch. Repeated swimming or showering is inconsistent with both its construction and the character of its most typical straps.

March LA.B offers several strap and bracelet materials including alligator, lizard and a seven-link steel bracelet. Leather straps incorporate a tool-free quick-release system, while the steel bracelet uses angular links that visually continue the facets of the case. Its inner surfaces are shaped to support comfort and ventilation. The seven-link bracelet turns Mansart most completely into a unified architectural object. Leather, by contrast, preserves more of its French dress-watch character while reducing total weight substantially.

Movements: from Miyota 90S5 to La Joux-Perret G100 and G121

The original 2019 automatic Mansart uses the Japanese Miyota 90S5, an automatic no-date calibre from the 9000 family. It operates at 28,800 vibrations per hour and provides approximately 42 hours of power reserve. Removing the date allowed March LA.B to retain an exceptionally clean dial on early Magnum and Steel variants. Miyota 90S5 was a pragmatic choice that allowed March LA.B to launch a relatively thin mechanical Mansart at a controlled price. Its proven reliability and widespread servicing network were also useful, even though the movement itself contributed little to a specifically French watchmaking identity.

From the 2022 generation onward, March LA.B changes mechanical direction substantially by installing La Joux-Perret G100 in the Mansart Date. The movement is manufactured in Switzerland and assembled in Besançon by Humbert-Droz through the Franco-Swiss partnership promoted by the brand. It contains 24 jewels, measures approximately 24.6 mm in diameter by 4.45 mm thick and operates at 28,800 vibrations per hour. The move to G100 represents the most important mechanical upgrade in Mansart history. It also brings movement assembly significantly closer to the French production narrative developed by March LA.B.

G100 provides 68 hours of power reserve compared with approximately 42 hours for the original 90S5. March LA.B describes it as “weekend proof”, meaning that a fully wound watch removed on Friday evening can theoretically remain running into Monday. Hacking seconds are included and the brand states a rate target between -4 and +6 seconds per day for its movements. The 68-hour autonomy materially changes the ownership experience for someone rotating Mansart with other watches. Time and date need resetting much less frequently than on the earlier Miyota generation.

A green-tinted sapphire back provides a view of the automatic movement. Green has become an important March LA.B signature and gives the watch an instantly recognisable rear view compared with conventional colourless exhibition backs. G100 remains a modern industrial calibre rather than a hand-finished haute-horlogerie movement. The green display back nevertheless turns the mechanics into a brand-specific visual element. It also connects naturally with the Grall and Forest colours frequently used across March LA.B dials.

Mansart Small Seconds introduces La Joux-Perret G121 in 2025. March LA.B describes it as a Swiss automatic small-seconds movement that is likewise assembled in Besançon. It has 24 jewels, operates at 4 Hz and provides approximately 68 hours of power reserve. G121 allows Mansart for the first time to integrate a mechanical small seconds directly into its design language. This makes the 2025 evolution significantly more coherent than a cosmetic dial variation because the visual change corresponds to a genuinely different movement architecture.

Mansart Electric instead uses the quartz Ronda 1063 with hours and minutes. The absence of a seconds hand reinforces visual minimalism and also removes the obvious once-per-second jump associated with many traditional quartz watches. Ronda 1063 primarily allows Mansart thickness to fall to approximately 8 mm. For someone prioritising shape, precision and immediate readiness on the wrist, the quartz watch therefore has a genuine reason to exist rather than merely representing a simplified mechanical Mansart.

Chronological milestones and main models (2019–2026)

(2019) March LA.B Mansart Magnum Birth of the Collection at Baselworld:

The March LA.B Mansart Magnum is one of the automatic versions accompanying the new collection’s presentation at Baselworld 2019. Its octagonal steel case measures 34 mm wide and approximately 39 mm long, with a profile close to 10.7 to 11 mm and 50 metres of water resistance. A gold-toned guilloché dial establishes a much more formal direction than the strongly seventies-inspired AM2 watches that had helped define March LA.B. The automatic Miyota 90S5 operates at 4 Hz and provides approximately 42 hours of reserve. A green-tinted transparent back reveals the movement. The first Mansart range combines mechanical Magnum and Steel versions with several electric executions, immediately establishing the design as a broader platform rather than one isolated reference.

(2020) March LA.B Mansart Millésime Mars First Dedicated Annual Edition:

The March LA.B Mansart Millésime Mars 2020 becomes the first watch used for the annual March edition concept, the month being closely connected with the origins of the March LA.B project. Limited to 50 pieces, this Mansart retains the compact octagonal case and automatic movement of the first generation but introduces a highly recognisable lacquered green dial accented by black guilloché. Green was already central to the visual identity of the brand, and this edition helps establish Mansart among its most recognisable creations. Selecting the collection to inaugurate Millésime Mars also demonstrates the importance acquired by the 2019 design within only one year, making it a preferred vehicle for March LA.B’s Franco-Californian identity.

(2022) March LA.B Mansart Automatic Grall Date Adoption of La Joux-Perret G100:

The March LA.B Mansart Automatic Grall Date MANSARTAGLDLE01 marks a fundamental technical change by introducing the La Joux-Perret G100 assembled in Besançon. The 316L stainless-steel case remains around 34 x 39 mm with 50 metres of water resistance, but the movement increases power reserve to 68 hours, adds a date and provides hacking seconds. The green Grall dial uses a sandblasted surface and a 3 o’clock date aperture whose numeral 3 can appear in green on the third day of the month. This generation reflects a broader change in March LA.B’s strategy: movement manufacturing remains industrial and Swiss, but final assembly moves closer to the French production story through Humbert-Droz in Besançon, giving the collection a more structured Franco-Swiss identity.

(2022) March LA.B Mansart 18-Carat Gold First Precious-Metal Family Execution:

In 2022, the March LA.B Mansart is also selected for the company’s first significant move into solid precious metal. A limited edition is produced with an 18-carat gold case, dark green or white dial and gold hour markers, with each configuration announced in a run of only 20 watches. The automatic La Joux-Perret G100 retains its 68-hour power reserve and remains visible through the back, while the black alligator strap is manufactured in France. The importance of the watch lies less in production volume than in positioning: a compact shaped watch originally introduced at a relatively accessible level has become sufficiently important to carry March LA.B’s first solid-gold proposition, demonstrating that the Mansart geometry can operate convincingly in a substantially more luxurious register.

(2025) March LA.B Mansart Small Seconds Grall New G121 Calibre:

The March LA.B Mansart Small Seconds Grall MANSARTAGLSS710 launches in September 2025 and evolves the case to 35 x 39 mm. Its green dial receives horizontal guilloché and an octagonal small-seconds register directly echoing the angles of the case. The movement becomes the 24-jewel La Joux-Perret G121 operating at 4 Hz and providing approximately 68 hours of reserve, with assembly in Besançon. Grall can notably be paired with the seven-link steel bracelet, while leather configurations are also available. The development is compelling because it is coherent: March LA.B does not simply add a complication but redesigns dial, proportions and internal architecture so the small seconds appears to have always belonged to the geometric language of Mansart.

(2025) March LA.B Mansart Small Seconds Golden Hour Gold-Plated Two-Dial Interpretation:

The March LA.B Mansart Small Seconds Golden Hour MANSARTAGDAL01 is the most visually assertive interpretation of the 2025 generation. Its 35 x 39 mm case receives a stated 3-micron gold plating and is paired with a black alligator strap. G121 retains 68 hours of autonomy and the screwed green-tinted display back. Golden Hour is also supplied with two guilloché dials, one light gold and one dark green; dial changes are performed through the brand or boutique rather than directly by the owner. The concept introduces a degree of personalisation while preserving the Small Seconds architecture shared with Grall and Shelter. It is also the most luxurious expression of the current Mansart range outside the earlier solid-gold limited editions.

(2026) March LA.B Mansart Expanded Family and Watches and Wonders Presence:

By 2026, the March LA.B Mansart is one of the main pillars of the catalogue as the brand participates in Watches and Wonders Geneva. The men’s line continues to combine 34 x 39 mm Automatic Date watches with G100, 35 x 39 mm Small Seconds models with G121 and 34 x 39 mm Electric versions with Ronda 1063. At the same time, the octagonal language has spread into Lady Mansart, Milady Mansart and, in September 2026, the new Mini Mansart measuring only 19 mm. This multiplication of formats demonstrates that the form created in 2019 has moved beyond the status of an isolated model. It now acts as a genuine design signature through which March LA.B can combine quartz, automatic movements, small seconds, steel, leather, gold tones and multiple case sizes around one consistent geometry.

Specialist media view

The Watch Observer described Mansart as a “Baselworld 2019 favourite” immediately after its launch and later emphasised the particularly strong personality of the design. That assessment is significant because it predates the octagonal form becoming an established signature within the March LA.B catalogue. The publication also noted the restrained dimensions, treating them simultaneously as an advantage and as a potentially polarising choice for wearers accustomed to larger watches. Mansart was consequently perceived from the beginning less as a universally consensual watch than as a distinctive design object capable of standing on the strength of its geometry.

Montres de Luxe summarised Mansart Small Seconds with the phrase “the chic of shaped watches”. That description suits the 2025 evolution particularly well: the model does not become sportier or technically ostentatious, but develops its dress-watch character through a small-seconds display, guilloché dials and G121 calibre. The publication also emphasises the combination of retro and contemporary qualities that has defined Mansart since its creation. The complication therefore does not transform the identity of the watch; it clarifies its architectural inspiration and its positioning between French design and Swiss mechanics assembled in Besançon.

Le Calibre describes the new generation as being “between class and modernity” and views the move to a La Joux-Perret movement as an important step for March LA.B. It particularly highlights the coherence between the octagonal seconds counter and the case architecture, together with the company’s attempt to move further upmarket without abandoning relative accessibility. This interpretation matches the broader Mansart story: a 2019 design originally powered by Miyota evolves into a platform capable of carrying more ambitious Franco-Swiss movements, more elaborate finishing and more precious executions while preserving its compact dimensions.

Choosing the right version: Automatic Date, Small Seconds or Electric

Mansart Automatic Date is probably the most versatile version for someone seeking modern mechanics without introducing excessive visual complexity. G100 provides 68 hours of autonomy, the dial remains highly legible and the 34 x 39 mm case retains the historical proportions of the family. Grall Date is the most coherent starting point for discovering the current mechanical Mansart. Its green dial also uses the colour most directly associated with March LA.B.

Small Seconds is more appropriate for an enthusiast wanting a more overtly horological dial and a clearly visible development of the concept. Its octagonal register, horizontal guilloché and G121 create additional visual depth at the cost of one extra millimetre of width and a higher price. Small Seconds is the most developed Mansart when interest lies equally in dial architecture and case shape. Grall emphasises personality, Shelter restraint and Golden Hour a much more luxurious presence.

Electric is instead the most rational solution when the design matters more than mechanics. Ronda 1063 allows thickness to fall to approximately 8 mm, the lack of a seconds hand avoids the visible one-second stepping of conventional quartz and the watch requires very little attention in everyday use. Electric is the thinnest, simplest and generally most accessible Mansart. Its aesthetic appeal remains largely intact because the case, crown and proportions are immediately recognisable.

The decision between leather and steel deserves a real wrist trial. Lizard or alligator reinforce the slimness and French dress-watch character, while the seven-link bracelet gives Mansart a much more constructed and contemporary presence. Total weight can almost double between certain configurations. The steel bracelet makes most sense for someone wanting Mansart to function as a more assertive everyday watch. Leather is preferable when lightness and the ability to slip easily beneath a cuff matter most.

Finally, the 50-metre water-resistance rating should keep the actual purpose of the collection in perspective. Mansart can comfortably handle the ordinary accidents of daily life but is neither a sports watch nor an aquatic instrument. Dial legibility should also ideally be assessed in person because textured and gold surfaces can react strongly to changing light. The best choice is the combination of dial, strap and movement that actually fits the circumstances in which the watch will be worn. Other customers’ opinions are essential.

Conclusion

The March LA.B Mansart successfully turns a distinctly French architectural reference into an instantly recognisable shaped watch without relying on a large case or a spectacular complication. Since its Baselworld launch in 2019, the concept has evolved from a Miyota 90S5-powered two-hand automatic into G100 La Joux-Perret date watches and G121 Small Seconds models, both associated with movement assembly in Besançon and 68 hours of reserve. Electric versions meanwhile preserve a thinner and simpler alternative. With 34 or 35 mm of width, a 4 o’clock crown, alternating polished and brushed facets, green display back and straps visually integrated with the case, Mansart has become less a single reference than a genuine design language now extending across several sizes and uses.

To compare comfort across the different sizes, G100 and G121 accuracy, textured-dial legibility, bracelet quality and the real everyday ownership experience, Dialicious customer reviews provide a particularly useful complement.

(Updated October 2026)