LOO Adjustable Screw On Pin Watch Opener Professional Type Watch Case Back Opener Wrench For Waterproof Watches / Change Battery Or Watch Movement You Self Open & Close Most Regular Size (Up To 37mm ) Waterproof Watch Cases 18 Pins (6 Sets Of 3 Pins) Can Open Slotted Cases, Rolex Watches, Cases With Holes And More This Table Is Open 6 Sets Of Steel Teeth With A Set Of Three. Can Easily Replace Chucks Are Quality Made They Guarantee Not Fall Off When Use