Audemars Piguet Selfwinding Chronograph

Audemars Piguet's Royal Oak Selfwinding Chronograph, reference 26240ST.OO.1320ST.05, is a chronograph with a 41 mm steel case. The case measures 6.8 mm thick and carries a blue dial under a sapphire crystal. Inside is the self-winding calibre 4401, developed by Audemars Piguet for this line of chronographs. The movement drives a flyback chronograph with small seconds and a date function, allowing the running seconds sub-dial to time short intervals independently of the main hands. A folding clasp closes the steel bracelet, which matches the case in finish. Water resistance is rated to 50 metres, modest for a sports model but standard for this reference.