Material: Made from Plastic with a sturdy soft sticky exterior and comes with an extra metal pump needle to inflate and deflate the ball Easy to Use: This Watch Case Opener Ball Allows you to have great grip on the Surface, Opens wiothout Scratching. Hold the watch in one hand and press the ball with your other hand to the watch case. Start twisting to unscrew the watch back cover case.This is a watch repair tool, not a toy! Compatibility: Perfect Size fits any watchmaker hand Inflateable and Defalteable as per your Requirement Product provided by MMOBIEL - We always try our best to exceed your expectations at every turn. Join the ever growing list of satisfied customers and discover the difference with MMOBIEL.