First presented in 2015, the MB&F LM Perpetual is one of the brand’s absolute superstars. This watch was awarded the Best Calendar Watch prize at the 2016 Grand Prix d'Horlogerie de Genève, recognizing the work from independent watchmaker Stephen McDonnell that collaborated with MB&F on the development of this watch that took years to complete. Developed from scratch this perpetual calendar is very different from conventional ones that rely on modules placed on top of an existing movement and where the indications are synchronized by a long lever —called 'grand levier' in French— running across the top of the complication and passing through the center. McDonnell pretty much reinvented the perpetual calendar mechanism, delivering a more user-friendly, more robust, and incredibly beautiful! machine.

 Since 2015, various limited editions have been announced and sold out. The MB&F LM Perpetual has been released in series of 25 pieces in platinum, rose gold, white gold with a purple dial, and yellow gold, and in a 50-piece limited edition in titanium with a blue-greenish dial.

LM Perpetual features a fully integrated 581-component calibre —no module, no base movement— with a revolutionary new system for calculating the number of days in each month. And it holistically reinterprets the aesthetics of the perpetual calendar by placing the full complication on a dial-free display underneath a spectacular suspended balance.

The choice of palladium was not an easy one; surprisingly, the cost of the raw material surpasses today both gold and platinum, and it is significantly more difficult to machine than platinum, making these 25 pieces a true challenge to craft. Depending on the light, the subtle aquamarine dial varies from light blue to grey to pale green. Additionally, this limited edition inherits two new features first seen on the LM Perpetual EVO editions, including more ergonomic corrector pushers and a darker movement finish on the back.

LM Perpetual turns the traditional perpetual calendar system on its head by using a “mechanical processor” instead of the conventional space-consuming ‘grand levier’ system architecture. The mechanical processor utilizes a default 28-day month and adds extra days as required. This means that each month always has the exact number of days required; there are no fast-forwarding or skipping redundant days. And while the leap year can only be set on traditional perpetual calendars by scrolling through up to 47 months, LM Perpetual has a dedicated quickset pusher to adjust the year.

With its open dial revealing the full complication and suspended balance, it's the harmonious mechanical beauty of LM Perpetual that really steals the show. And in an interesting technical twist, that eye-catching balance hovering on high is connected to the escapement on the back of the movement by what is likely to be the world's longest balance staff.

Using an innovative system developed especially for Legacy Machine Perpetual, the subdials appear to "float" above the movement with no visible attachments. The skeletonized subdials rest on hidden studs, which is technically impossible with traditional perpetual calendar mechanisms because they would block the movement of the grand levier. Taking a clockwise tour of the dial, at 12 o'clock we see the hours and minutes nestled between the elegant arches of the balance; day of the week at 3 o'clock, power reserve indicator at 4 o'clock, a month indicator at 6 o'clock, retrograde leap year indicator at 7 o'clock, and date at 9 o'clock. The new MB&F Legacy Machine Perpetual Palladium with Aquamarine Dial is available via the MB&F AD network and through their e-shop.

Sticker Price $206,000 USD. For more info on MB&F click here.