Rolex Day-Date 228236-0012 40mm

Case
Oyster (monobloc middle case, screw-down case back and winding crown)
Diameter: 40 mm
Material: 950 platinum
Middle case: 950 platinum, polished finish
Bezel: 950 platinum, fluted
Case back: 950 platinum, solid, screw-down with fine fluting
Winding crown: Twinlock in 950 platinum, screw-down, double waterproofness system
Crystal: Scratch-resistant sapphire with anti-reflective coating; Cyclops lens over the date with double anti-reflective coating
Waterproofness: 100 metres (330 feet)

Movement
Calibre 3255, Manufacture Rolex
Mechanical movement with bidirectional self-winding via Perpetual rotor
Precision: -2 /+2 sec./day, after casing
Oscillator Frequency: 28,800 beats/hour (4 Hz)
Paramagnetic blue Parachrom hairspring
Rolex overcoil
Large balance wheel with variable inertia
High-precision regulating via four gold
Microstella nuts
Traversing Balance Bridge
High-performance Paraflex shock absorbers
Escapement: Chronergy with optimized energy efficiency
Paramagnetic nickel-phosphorus pallet fork and escape wheel
Jewelling: 31 rubies
Power reserve: Approximately 70 hours

Functions
Centre hour, minute and seconds hands
Instantaneous day and date in apertures at 12 and 3 o’clock with secure rapid-setting
Stop-seconds for exact time setting