Stainless steel handy tool for winding up your watch. Crown on your watch is small and difficult to wind, makes winding up of all watches easier. Stainless steel construction of , push at to open the jaws to fit most small to large crowns. This has spring mechanism, you push a side that opens the clamp, place on the crown then the spring holds the waterproof crown for winding. Color: steel This tool can be used on the following points: Winding your mechanical watch very easy and fast. Set the time or date of the watch in just a few seconds. Adjustable, each size can use in 3 or 4 dimensions of the crown Just press the piston on the head and the jaws lock to the crown of two-tone presidential watches. Allows you to set the date quickly. Size: 4.0 mm The package contains: 1 X size winder of the crown Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.