100% brand new and high quality Made of steel material, the size is 70mm x 28mm x 11mm and the ends can be adjusted from 13mm to 56mm to fit watch cases of different sizes. It is the most effective tool for opening the watch case. Fun to DIY - Replacing a battery at a jewelry store can be very expensive. You can do it yourself now with this easy to use clock tool kit! WIDELY USED - Great tools for opening waterproof watch case, from replacing batteries and repairing watch. The watch holder tool will reduce the risk of slipping and scratching. Long-lasting, made of strong material that gives the opener a long service life. It is also waterproof and will not rust or get damaged easily. Specifications of Watch Case Back Opener Material: Stainless Steel Size: 70mm x 28mm x 11mm (L x W x H) Adjustable jaw distance from 11mm to 54mm. Small size and easy to use. Works great on watches that are 99% waterproof (with notches on the back). How to use: Turn the black knob and make it fit tightly around the watch face plate. Then turn the adjustment wheel of the watch case back opener to adjust the distance between the bits to fit the grooves of the case back of your watch. Just twist it and the watch case cover will open. Package Contents: Watch Case Opening Tool