316L Surgical-Quality Stainless Steel Case Jeweled M2701-1A Automatic Movement Jewel Bearings: 22 Jewels 41 Hour Power Reserve Beats per Hour (BPH): 21600/Hour Sapphire-Coated Mineral Crystal Semi-Skeleton Dial Observation Case back to view Movement Genuine Leather Strap Logo-Engraved Stainless Steel Clasp 46mm Diameter 5 ATM Water Resistance