A decade after its debut, MB&F revisits one of the most consequential perpetual calendars of the past twenty years with a trio of limited editions that bring high jewelry into conversation with mechanical processor architecture.

Without a doubt, one of the biggest launches of 2015 was when MB&F unveiled the Legacy Machine Perpetual—the brand's first perpetual calendar and the recipient of the Calendar Prize at the 2016 Grand Prix d'Horlogerie de Genève. Developed from scratch with independent Irish watchmaker Stephen McDonnell, the LM Perpetual broke decisively from convention by retiring the grand levier in favor of a fully integrated, dial-side complication. We've followed its evolution closely ever since—from the Palladium with aquamarine dial and Yellow Gold editions through the Stainless Steel Salmon Dial, the recent LM Perpetual Longhorn, and the gem-set LM Perpetual EVO Baguette Diamonds Seddiqi Limited Edition. For 2026, the LM Perpetual takes a brighter turn with the Chromatic Editions—three new references that frame the dial-side architecture in a hand-set baguette gemstone bezel without altering a millimeter of the case.

Things to Know About the Watch

The new MB&F LM Perpetual Chromatic series consists of three references, each limited to just 8 pieces—by a meaningful margin among the rarest LM Perpetuals ever produced. Two editions are housed in 18K white gold, fitted with bezels set with either blue sapphires—1.95 carats, from Madagascar and Sri Lanka—or purple sapphires—1.93 carats, from Madagascar. The third edition arrives in 18K red gold, set with red rubies—1.95 carats, from Mozambique.

Each bezel carries 48 baguette-cut gemstones, all hand-set in Geneva by STG Création—a long-term MB&F partner. The result is an unbroken chromatic frame around the open dial, achieved without expanding the established 44 mm case diameter. Hands are PVD-treated to match the purple, blue, and 5N finishes to echo the red-gold case. Dimensions remain 44 mm x 17.5 mm and are water-resistant to 30 meters.

The Movement

The LM Perpetual Chromatic editions are powered by the same fully integrated 581-component, manual-wound calibre that has anchored the LM Perpetual since 2015. Rather than treating the perpetual calendar as a module bolted atop a base movement, McDonnell built the entire architecture around a "mechanical processor"—a stack of superimposed disks that, each month, defaults to 28 days and adds the required days from there, rather than scrolling past redundant ones. The calendar cannot mis-jump; its quickset pushers disconnect during changeover; and the year can be set independently in seconds rather than scrolled through 47 months.

The movement provides a 72-hour power reserve from twin mainspring barrels, with hand-engraved bridges, internal bevels, and Geneva waves throughout. The 14 mm suspended balance is connected to the escapement via what MB&F describes as likely the longest balance staff in series production, which remains the visual signature beneath the new gemstone frame.

Summary & Price

In a collection now numbering twelve distinct executions, the Chromatic trio stakes out fresh aesthetic territory for the LM Perpetual without touching the mechanics that made the original a modern classic. Eight pieces per reference is a vanishingly small number for a watch of this stature. Here is the full list of LM Perpetual executions to date:

Platinum with blue dial — limited to 25 pieces
18K red gold with grey dial — limited to 25 pieces
18K white gold with purple dial — limited to 25 pieces
18K white gold with dark grey dial — unlimited
Grade 5 titanium with green dial — limited to 50 pieces
18K yellow gold with blue dial — limited to 25 pieces
Palladium with aquamarine dial — limited to 25 pieces
Stainless steel with salmon dial — unlimited
Stainless steel with diamond-set bezel — exclusive to Ahmed Seddiqi, 5 pieces
18K red gold with red rubies bezel — limited to 8 pieces (new Chromatic)
18K white gold with blue sapphires bezel — limited to 8 pieces (new Chromatic)
18K white gold with purple sapphires bezel — limited to 8 pieces (new Chromatic)