The Audemars Piguet Royal Oak Chronograph (Ref.26240ST.OO.1320ST.08) is a refined 41mm stainless steel men's/unisex timepiece. It's powered by the automatic caliber 4401 movement, offering a 70-hour power reserve and 40 jewels for exceptional chronograph performance. The signature octagonal bezel and steel screws are instantly recognizable. With a 5 ATM water resistance, this Royal Oak Chronograph in steel with its vibrant green dial is a statement of modern sporty elegance.