Overview

White Quartz TPT® case with the RMUL4 calibre

The White Quartz TPT® execution is one of the three colourways in which the RM 55-01 Manual Winding was launched in 2026, alongside Carbon TPT® and Grey Quartz TPT®. The composite is built from silica threads rather than carbon; Quartz TPT® fibres are used industrially for their resistance to high temperature, their strength and their transparency to electromagnetic waves. The bezel and caseback are the composite and the case middle is titanium.

The calibre is the RMUL4, a manual winding skeletonised movement weighing under five grams and indicating hours, minutes and seconds. It is held by four microblasted titanium spline screws within the three-part tonneau case, with rhodium-plated hands moving above a four-part flange in titanium, carbon fibre and steel.

Key details

Design and engineering

• Calibre RMUL4Manual winding skeletonised movement with hours, minutes and seconds. Movement dimensions are 31.25 × 29.45 mm with a thickness of 3.46 mm, running on 26 jewels at 28,800 vph (4 Hz), and the whole weighs under five grams.
• Quartz TPT® caseSilica threads are divided into layers no thicker than 45 microns, saturated in resins developed for Richard Mille, and stacked by an automatic positioning system that rotates the fibre orientation by 45° between layers. The stack is heated to 120°C under 6 bar of pressure and then CNC-machined at the brand’s own facilities.
• Baseplate and bridges in grade 5 titaniumThe baseplate is grade 5 titanium, microblasted and sanded; the going train is held by three bridges, also grade 5 titanium, sanded and treated with Titalyt®. The thicker satin-brushed structural parts are worked to the same tolerances.
• Free-sprung balance with variable inertiaThe regulator index is eliminated and calibration is made by four small adjustable weights fitted directly to the balance. The balance is Glucydur®, four arms, moment of inertia 4.8 mg·cm², angle of lift 53°, with an elinvar balance spring by Nivarox® and a Triovis No. 2 index assembly.
• Double-barrel systemTwo barrels share the stored energy, increasing rotations and reducing pressure on teeth, bearings and pivots.
• Flanges and crystalsThe upper flange is grade 5 titanium with index points filled with approved luminous material; the lower flanges are polyamide and 316L stainless steel. Both crystals are sapphire at 1,800 Vickers with anti-glare treatment on both faces.

Specifications

Technical specifications

Buying with HYPA

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• Manufacturer warranty confirmed from the warranty card
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• Registered Australian dealerHYPA International Pty Ltd · Victorian Second-Hand Dealer Licence SHD-0018017.
• Direct specialist supportSpeak with the HYPA team before, during and after the purchase.

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Related references

RM 55-01

Richard Mille · RM 55-01

RM 056

Richard Mille · RM 056

RM 056

Richard Mille · RM 056 Sapphire