Quick summary
- MB&F has introduced three LM Perpetual Chromatic editions for 2026, each limited to 8 pieces worldwide.
- The watches combine the Legacy Machine Perpetual’s open, fully integrated calendar movement with baguette-cut ruby or sapphire bezels.
- Pricing is CHF 228,000 plus VAT, with US pricing listed at $312,000 and European pricing at €248,000 plus tax.
MB&F’s 2026 LM Perpetual Chromatic editions bring a sharp hit of gemstone colour to one of the most important perpetual calendars of the last decade.
There are three versions, with blue sapphires or purple sapphires set into 18k white gold cases, and Mozambican rubies set into an 18k red gold case.
Three rare LM Perpetuals with a harder colour edge
The Legacy Machine Perpetual has always been a technical watch first, but the Chromatic editions shift its personality without diluting the mechanics.
Each bezel carries 48 baguette-cut stones, forming a continuous ring of colour around the 44 mm case.
The blue sapphire version uses stones from Madagascar and Sri Lanka, the purple sapphire edition uses Madagascar sapphires, and the ruby model uses Mozambican rubies.
Setting baguette stones this cleanly is unforgiving work because every rectangular stone has to sit flush with its neighbour and maintain the same visual rhythm around the bezel.
The open dial remains the real theatre
The LM Perpetual doesn’t use a conventional dial, and that’s still one of the reasons it feels so different from traditional high-end perpetual calendars.
Instead, the movement architecture becomes the display, with skeletonised subdials appearing to float above the mechanism on hidden supports.
The layout keeps the hours and minutes at 12 o’clock under the suspended balance, with the day at 3, power reserve at 4, month at 6, retrograde leap year at 7, and date at 9.
MB&F also matches the hands to each version, using purple, blue or 5N gold-toned PVD treatments to echo the stones and case metal.
Stephen McDonnell’s calendar still sets the watch apart
The calibre inside these Chromatic editions is the 581-component manually wound perpetual calendar developed by Stephen McDonnell for MB&F.
Its central idea remains unusually elegant for such a complicated watch.
Rather than treating every month as 31 days and mechanically skipping unwanted dates, the movement works from a 28-day month and adds only the extra days required.
That logic removes the familiar end-of-month fast-forwarding drama of many perpetual calendars and helps protect the mechanism during adjustment.
The movement also includes safety features that disengage the quickset pushers during the date changeover period, plus a dedicated pusher for year adjustment.
A large 14 mm balance wheel beats above the dial at 18,000 vibrations per hour, while double mainspring barrels provide a 72-hour power reserve.
MB&F LM Perpetual Chromatic key specifications
| Model | MB&F LM Perpetual Chromatic Editions |
|---|---|
| Case | 18k white gold with blue sapphires, 18k white gold with purple sapphires, or 18k red gold with rubies |
| Dimensions | 44 mm diameter, 17.5 mm height |
| Gem setting | 48 baguette-cut stones on the bezel |
| Gem carat weight | 1.95 ct Mozambican rubies, 1.95 ct blue sapphires from Madagascar and Sri Lanka, or 1.93 ct purple sapphires from Madagascar |
| Movement | Manual-wind integrated perpetual calendar calibre by Stephen McDonnell |
| Components | 581 movement components, 69 case components |
| Jewels | 41 |
| Frequency | 18,000 vph, 2.5 Hz |
| Power reserve | 72 hours |
| Functions | Hours, minutes, day, date, month, retrograde leap year, power reserve |
| Crystal | Sapphire front and display back with anti-reflective treatment on both faces |
| Water resistance | 30 metres |
| Strap | Hand-stitched alligator strap with folding buckle matching the case material |
| Limited edition | 8 pieces per version |
| Price | CHF 228,000 plus VAT, US$312,000, or €248,000 plus tax |
The finishing remains in line with the broader LM Perpetual family, with polished bevels, Geneva waves, internal angles and hand engraving visible through the sapphire back.
For collectors, the appeal is the way the gems frame the watch rather than overwhelm it.
This is still the LM Perpetual that won the 2016 GPHG prize for Best Calendar Watch, only now with a much more vivid perimeter and an even narrower production run.
With just 24 watches across all three Chromatic editions, these are unlikely to spend much time in boutique windows.
FAQ
How many MB&F LM Perpetual Chromatic watches will be made?
MB&F will produce 8 pieces of each Chromatic edition, making 24 watches in total across the ruby, blue sapphire and purple sapphire versions.
What is different about the LM Perpetual Chromatic editions?
The defining change is the baguette-set gemstone bezel, offered with Mozambican rubies, blue sapphires, or purple sapphires depending on the case version.
Who developed the LM Perpetual movement?
The movement was developed for MB&F by independent watchmaker Stephen McDonnell and uses a fully integrated architecture rather than a perpetual calendar module added to a base calibre.
What is the price of the MB&F LM Perpetual Chromatic?
The listed retail price is CHF 228,000 plus VAT, with US pricing at $312,000 and European pricing at €248,000 plus tax.
