Seiko SRP637K1 Men’s Prospex Monster Baby Tuna Diver’s 200M Watch. Japan automatic movement with manual winding capacity. Caliber: 4R36. 24 jewels. Power reserve: Approx. 41 hours. Accuracy: +45 to -35 seconds per day. Stainless steel case. Unidirectional rotating bezel. Stainless steel bracelet. Black dial. LumiBrite on hands and indexes. Day and date display at 3 o’clock position. Screw down crown. Stop seconds hand function. Hardlex glass. Water resistance up to 200 meters for diving. Approximate case diameter: 48mm. Approximate case thickness: 13.8mm.