Features: Adopting premium metal construction, anti-rust and stable. Adjustable, the crown winder fits most watch crown, winding your mechanical watch easily and fast. There are 4 different size, you can get suitable one. Can be used when letting down the mainspring when working on mechanical watches. Easy and handy to take with you because its small size and light weight. Specifications: Material: Metal Color: Shown As Pictures Length: Approx. 8cm / 3.1inch Optional Caliber: 3mm / 0.1inch, 3.5mm / 0.1inch, 4mm / 0.2inch, 4.5mm / 0.2inch Weight: 27 - 28g Type: Tools & Repair Kits Function: Repair Watch, etc Package Includes: 1 x Watch Crown Winder Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.