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″ Armor Plate Steel. There is a round and a square spinner target. Each has a 4″ top and 5″ lower target. Solid steel frame. Designed to fit with Allen Custom Target System brackets. Horizontal braces keeps frame upright.F