Multifunctional Watch Back Case Backing and Glass Mounting Machine, 13 Deep Aluminum Dies, 18mm-46mm, 4 Plastic Dies for Square Watch Cases, Multi-Purpose Chain Link Remover Accessory: This multifunctional machine is an indispensable tool for watch repairs. It includes 13 deep aluminum dies, from 18mm to 46mm, and 4 plastic dies for square watch cases.