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 good quality, push at to open the jaws to fit most small to 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.