The 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.