SincereetaliThis is a case opener for waterproof watches. The tips can be adjusted from 13 to 56 mm, which can accommodate cases of different sizes. Compact and small, making it very convenient to carry. Features: Minimize the risk of slipping and scratching. Water resistant and will not rust or damage easily. The tips can be adjusted from 10 to 50 mm to fit cases of different sizes. Compact and small, making it very convenient to carry. Ideal for opening waterproof watch cases, replacing batteries and repairing watches. Specifications: Material: Stainless Steel Optional Type: 2 Types Optional Item Weight: 45g / 1.59ounce Package Weight: 80g / 2.82ounce Item Size: 70 * 40 * 15mm / 2.76 * 1.18 * 0.59in Package Size: 80 * 50 * 20mm / 3.15 * 1.97 * .79in How to Use: Turn the black knob and adjust it around the watch face plate. Then roll the adjustment wheel of the watch back opener to set the tip spacing to match the grooves on your watch case. Simply turn it to open your watch case. Package List: 1 * Watch Back Case Opener