Yonger Watch Back Case Opener Remover Removal Knife Repair Tool (Yellow) Made of Durable Stainless Steel and Plastic. Watch Opener Configured to Make Opening Certain Cases Easier. This Pocket Watch Opener Is Popular and Many Watchmakers' Ideal Tool. Simply Place The Blade Under The Case Back and Pry It Off. Size: 3.12*1.76*0.78.