Adjustable watch back cover opener can easily remove or screw down the waterproof watch back cover to replace the battery or repair the watch. It is a necessary tools for watchmakers and watch repairing workers The jaw distance can be adjusted between 10.5mm and 65mm, it be used to open waterproof watches of different sizes. (NOTE : It be used to open and close most screw-in watch back cases, can not be used for watches that pry open the bottom cover directly) Watch Case Opener Tool have a Perfectly Weighted Feel and HIGH QUALITY Durability. The strong Alloy Steel and Brass Plating is designed for tough use, so it is much sturdy and more than other similar products No complicated operation, you just need to fix the watch on the repair bracket or hold firmly in the hand, then roll the adjusting wheel to set the bit spacing that matches the width of the case. After installing the watch case opener, try turning the watch back cover, The cover can be opened successfully Type: B: Square Beak color:Silver Material:Metal Package Contents: 1 x watch back remover tool Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.