Name: Medium round head ring Knuckle DusterSpecifications: Width (bottom of the hand): 90mm (finger width): 97mmHeight (fist arc to bottom): 62mm (finger hole size): 26*20mm Thickness (fist): 11mmWeight: about 113 grams Material: zinc alloy Craftsmanship: gold and silver are electroplated; black is sprayedFunction: martial arts defense and life-saving, simple function, no special training is required to master. Outdoor car self-defense, home standby first aid, easy to carry and does not take up space. It is a very good product