EZ-Aim Allen Steel Gong Hanger Target w/Recoil Spring 2 x 4in Mount 2.3 lbs Black Powder Coated. It fits most steel targets. The targets are best mounted with a center bolt hole. The recoil spring reduces the impact of the projectiles on the AR500 steel target by absorbing some of the energy. Attaches to the 2 x 4 lumber with a steel wedge that creates tension on the wood. Bolts and hardware are supplied to permanently mount it to the wood. Manufactured from powder coated steel. Specifications for EZ-Aim Allen Steel Gong Hanger Target w/Recoil Spring: Manufacturer: EZ-Aim Weight: 4.4 lb Included Accessories: Hardware/Recoil Spring Fabric/Material: Steel Features of Allen EZ Aim Steel Gong Hanger Target w/Recoil Spring Solid steel construction; Mounts to 2 x 4in lumber; Holds most steel targets with a center hole; Hardware included for permanent mounting; Package Contents: Allen EZ Aim Steel Gong Hanger Target Reciol Reducing Spring Kit Hardware EZ-Aim 15515: Allen Steel Gong Hanger Target w/Recoil Spring 2 x 4in Mount 2.3 lbs Black Powder Coated