Ramset 1516SDE Ramguard Pin with Washer, Steel, Zinc            Provides easier penetration into concrete, drywall and structural steel. 7/8 in washer prevents overdrive and increase holding value when fastening wood or thin metal to concrete or structural steel. Fits most powder actuated tools that use 22 cal. Single shots of 27 cal. Shank diameter of 0.145 in.