- Movement
- Manual winding, skeletonised
- Size
- 37.95 × 47.33 × 10.75 mm
Overview
Grey Quartz TPT® around the ultralight calibre RMUL4
An RM 55-01 Manual Winding in Grey Quartz TPT®, its layered finish reading pale blue-grey, on a grey woven strap with a white crown. Pink accents fill the hour points and the tips of the hands.
Richard Mille stripped the RM 55-01 back to absolute mechanical necessity. Its skeletonised calibre RMUL4 weighs less than 5 grams and winds by hand, showing hours, minutes and seconds. Two barrels share the stored energy for a power reserve of around 55 hours.
Key details
Case materialGrey Quartz TPT®
MovementCalibre RMUL4, manual winding
Power reserveAround 55 hours
Design and engineering
- Quartz TPT®Fibres aligned in layers no thicker than 45 microns, saturated in resins developed for Richard Mille. The fibre direction turns 45° between layers; the stack is heated to 120 °C under 6 bars, then machined on a CNC machine.
- Calibre under 5 gramsThe skeletonised RMUL4 weighs less than 5 grams and fits a case of conservative dimensions.
- Titanium baseplate and bridgesGrade 5 titanium baseplate, microblasted, sanded and black PVD coated; the going train is held by three grade 5 titanium bridges, sanded and Titalyt® treated.
- Double barrelThe stored energy is distributed across two winding barrels instead of one.
- Free-sprung balance with variable inertiaThe regulator index is eliminated; four small adjustable weights sit directly on the balance.
- Four-part flangeA complex four-part flange weaves together titanium, carbon fibre and steel.
The reference
Technical specifications
| Reference | RM 55-01 |
|---|---|
| Calibre | RMUL4 |
| Movement | Manual winding, skeletonised |
| Functions | Hours, minutes, seconds |
| Power reserve | Around 55 hours (± 10%) |
| Baseplate and bridges | Grade 5 titanium |
| Movement dimensions | 31.25 × 29.45 mm, thickness 3.46 mm |
| Jewels | 26 |
| Balance | Glucydur®, 4 arms, moment of inertia 4.8 mg·cm², angle of lift 53°; free-sprung, variable inertia |
| Balance spring | Elinvar by Nivarox® |
| Shock protection | Incabloc 908.22.211.100 |
| Frequency | 28,800 vph (4 Hz) |
| Case dimensions | 37.95 × 47.33 × 10.75 mm |
| Case material | Grey Quartz TPT® |
| Case construction | Three-part tonneau; calibre anchored by four microblasted titanium spline screws |
| Crystal | Sapphire, anti-glare both sides; sapphire case back |
| Strap | Grey woven |
Buying with HYPA
Purchase with confidence
- Warranty card status disclosed for every piece we sell
- Free insured delivery within Australia · international quoted
- Payment by bank transfer
- Registered Australian dealerHYPA International Pty Ltd · Registered Victorian second-hand dealer, Registration No. SHD-0018017.
- Direct specialist supportSpeak with the HYPA team before, during and after the purchase.
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