Parameters: Model:AM339M/AM339MS Case diameter:42mm Case thickness:13mm Lug to Lug distance:49.30mm Band width:22mm Wearable length:145~205m Case materail:Stainless steel Strap:Silicone /Stainless steel Clasp:Pin Buckle Lens:Sapphire glass Back cover material:Sapphire glass Movement:MIYOTA 8215 Water proof:200m (20ATM) Weigth:113g(Silicone Strap) Weight:182g(Stainless Steel Strap) Features: 1.Japan Miyota 8215 Automatic Movement. 2.Travel time accuracy (seconds/day): -20～+40 seconds.. 3.Self winding. 4.Day Date Calendar Watch. 5.Super luminous hour marker,Easy to read underwater and without light. 6.Double fluorescent bidirectional rotating bezel,Dual Fluorescence hands,Clear and intuitive, enhanced timing and security. 7.Silicone band deeply waterproof. 8.Surface lens and Exhibition Back cover material all are Sapphire Glass ,high light transmittance/ scratch resistance. 9.Screw-down crown ,200M Waterproof ，diving performance is better. 10.Timing Rotating Inner Ring，Compressor-Style  Diver Watch. Silicone Strap Versions: