BRAND : Audemars Piguet MODEL : Royal Oak Selfwinding Chronograph MODEL NUMBER : 26331ST.OO.1220ST.02 CASE : Stainless steel case, glareproofed sapphire crystal, screw-locked crown. CASE SIZE : 41 mm WATER RESISTANCE : 50 m DIAL : Black dial with “Grande Tapisserie” pattern, silver-toned counters, white gold applied hour-markers and Royal Oak hands with luminescent coating. CALIBRE : SELFWINDING CALIBRE 2385 MECHANISM : Selfwinding POWER RESERVE : 40 hours FUNCTIONS : Chronograph, hours, minutes, small seconds and date.