This watch case opener will open most waterproof watch cases. Includes 6 sets of different type of chucks, chucks will work on polygonal, slotted, hole, and grooved case back. Made of high quality metal to help form a tight grip when removing the metal case back from waterproof watches. Type: Watch Case Opener Wrench Material: Metal Features: Durable, Watch Repair Tool Compatible Case Dia.: 36mm - 37mm/1.42" - 1.46" (Approx.) Length: 14.5cm/5.71" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Watch Case Opener Wrench 18 x Pins (6 Sets of 3 Pins)