Seiko Auto 100m - SRPB37J-ST Movement: 4R36 - Automatic 24 jewels Made in Japan Case and bezel - stainless steel. Crystal: Hardlex Power reserve: 41 hours 21,600 vibrations per hour Screw case back Screw-down crown With black silicon strap in tyre threading Case reference: 4R36-06B0 Case diameter: 43.8mm Case thickness: 13.2mm 64-21051217769-TW