Zenith Grande Class Open

Ref. 03.0520.4021/21.C492: Stainless steel case with sapphire caseback, black dial, black rubber strap. El primero 4021h automatic movement with chronograph, power reserve indicator, open dial showing the escapement mechanism. Case diameter: 44 mm. Water-resistant to 50 meters. Stainless steel triple-folding buckle with zenith star on the cap.

http://www.zenith-watches.com