Scratch Resistant Hardlex Crystal -- Hand and Automatic Winding  capabilities -- 21,600 vibrations per minute -- 41hr Power Reserve -- 23 Jewels (Caliber 4R35) -- Case Diameter: 42.0mm -- Date Calendar -- Screw down see-through case back -- Black Leather Strap -- Buckle Clasp -- Band Width: 20mm -- Band Length: from 6 to  8.5 inches -- Water Resistant to 100m (330ft)