DAP DRAFTSTOP 812 Low Pressure/Non-Rigid Polyurethane Foam is available in 26 oz. gun grade and 9 oz. straw grade canister. DRAFTSTOP 812 is low pressure single component polyurethane foam designed to fill gaps between fenestration products and rough openings. It will provide an airtight seal and protect against water, air and sound intrusion. The non-rigid, highly elastic foam has 30% joint movement capability which accommodates movement and settlement to maintain an airtight, weather-proof seal. It is closed cell, minimal expanding foam which will not absorb water, warp or deflect window or door frames.