The Simpson Strong-Tie GW is a gas-actuated 1/2″ dome washer pin designed to fasten building components to concrete. The versatile GW consists of a 1/2″ dome washer and a pin of 1/2″, 3/4″ or 1″ in length. The GW is for high-volume applications and can be used with common powder-actuated tools for fastening into harder substrates (structural steel or extra-hard concrete) when required.