High quality nickel plated all metal tool for winding up your watch. It is spring loaded for ease of use. Excellent tool if the winder/crown on your watch is small and hard to wind, makes winding up all watches easier. Just push the end knob and jaws open to fit over stem. Knurled jaws hold the stem firmly. For watch stems approx. 3.5-5mm in diameter. 3″ long.