It concentrates the force of the strike into a hard, blow. This key chain is made from high-craft aluminum and has been finished with electroplating and then polished down to a nice finish. It fits ring sizes from the smallest sizes, up to sizes larger than size 16. Two holes, a palm reinforcement, and a key chain make this the perfect means of both impression and self defense. Overall Length: 2.75 Inches. Ring Size: 16+ Max. Construction: High-craft Aluminum, Two Hole. Finish: Electroplated, Polished Golden. Includes: Key Chain.