This is a waterproof watch case opener. The tips can be adjusted from 13mm to 56mm, which can fit different size watches. Compact and small, let you do very convenient. Features: minimizes the risk of slipping and grooves. Waterproof and will not easily rust or damage. Tips can be adjusted from 10mm to 50mm to fit different watch sizes. compact and small, allows you to make very convenient. Ideal for opening a waterproof watch case, replacing batteries and showing repairs. Features: Material: Stainless Steel / ABS Optional Type: 2 Types Optional Item Weight: 45g / 1.59oz Package Weight: 80g / 2.82oz Item Size: 70 * 40 * 15mm / 2.76 * 1.18 * 0.59in Packing size: 80 * 50 * 20mm / 3.15 * 1.97 * 0.79in Usage: Turn the black knob and make it tightly set the clock on the front panel. Then roll the case opening dial to adjust the spacing of the tips to match the grooves on the case back of your watch. Simply twist and the back case of your watch is open. List of packages: 1 * the return next opens the case