Sinn Spezialuhren 910 SRS

The Sinn 910 SRS, reference 910.020, has a 41.5 mm steel case and is a column wheel chronograph with a flyback function. The polished and satinised case is 15.1 mm thick with a see-through back, water resistant to 100 metres. Calibre Valjoux 7750 is self-winding. Sapphire crystal fronts a dial with hand-attached appliqués and small seconds. Polished chamfers edge the counter rings. A double scale indicates units per hour alongside the counters.