Friction Ball Watch Case Opener Open watch case backs with ease using this friction ball. Hold the watch in one hand and in the other hand, press the friction ball onto the back of the watch. Start twisting to unscrew the watch back. Inexpensive, easy-to-use and will not leave marks. 2-1/2 diameter. You can return this item for any reason and get a full refund: no shipping charges. The item must be returned in new and unused condition. Go to Your Orders to start the return Print the return shipping label Ship it!