Movement Caliber Breitling B15 (Manufacture) Movement Hand-wound Power Reserve Approx. 70 hours Chronograph 1/4-second, 30-minute counter Vibration Frequency 28,800 vibrations/hour Jewels 27 jewels Case Case Material Stainless steel Case Back Screw-down (sapphire crystal) Water Resistance 10 atm Bezel Fixed Crown Non-screw-down locking type, 2 gaskets, integrated push-buttons Glass Domed sapphire crystal with anti-reflective coating on both sides Dimensions Product Weight (approx.) 120.0 g Watch Head Weight (approx.) 97.9 g. Diameter 42.0 mm Thickness 15.3 mm Height (from top to bottom of lugs) 50.0 mm Lug Width (between lugs) 22.0 mm Strap/Bracelet Strap Material Alligator leather Strap Color Gold Brown Strap Type Curved Strap Size 22/18 mm Buckle Material Stainless steel Buckle Buckle-style Buckle Size 18 mm