Simpson GW50 R200 1 2" Dome Washer And 1 2" Step Shank Pin w Fuel Cell, Pkg 200 GDP Gas Actuated Concrete Pins W Fuel Cell Available in multiple lengths to Available in multiple lengths to accommodate varying project requirements These are designed for use with Simpson Strong Tie DCU composite deck screws and the Auto Set driver bit for a complete hidden deck fasteners system 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 The Simpson Strong Tie GW is a gas actuated 1 2" dome washer pin designed to fasten building components to concrete