Description: Description: 1. Universal wrench for watch back case opening and closing 2. Key for waterproof watch case, with 4 sets of clamps: Round, Flat, Square and Toothed 3. The tool is special movable screw-plug back cover of watch, easy to use, easy to carry. 4. The largest open table 3.70 cm in diameter. 5. Kit Qty: 18pcs 6. Main material: Steel 7. Opens watch backs from 17mm-37mm 8.Fully adjustable via thumb wheel Specifications: Features: Small three-jaw open with 6 groups of 3 each with a total of 18 steel teeth The tool is specially designed to open and close the screw-in back cover watch, which is easy to use and easy to carry. (tool for opening the lid watch) (Maximum open table diameter 3.70 cm, subject to the bayonet) 3.7*3.5cm This set of opener is equipped with 6 sets of steel teeth and a set of three. It can be replaced at will, and it can open most of the watches with the back cover of the common screw-in type. How to use: Open table will implement three steel teeth to adjust to the appropriate location, choose to suit oneself watches back cover bayonet shape, on the back cover bracket, then, with the hand to the table above pressure and rotate to the left, bottom cover can be opened. Package Included: 1 x Watch Back Case Opener Wrench Tool Kit Set 1 x Blue Storage Case