Economical watch case opener wrench will open and close most waterproof watch case backs. The wrench can be used for changing watch batteries, movements and more. The tool includes four sets of different type of pins to open various types of watches, round, flat, square and toothed. Easy to operate, the long handle twists to adjust to the size of the watch back. Watch case opener will open up to 38mm case backs. Made of Metal. Comes with convenient wooden storage box. Instructions Included Manufactured for Paylak Tools