The EZ Aim AR500 Hardrock double spinner is designed for use with any rimfire or high power rifle or handgun. Handguns should be used at 30-feet, rifles at 100-yards. The AR500 target faces are made from 1/4-inch Armor Plate Steel. There is a round and a square spinner target. Each has a 4-inch top and 5-inch lower target. Solid steel frame. Designed to fit with Allen Custom Target System brackets.