RD•DS 181 Acrylic Duct Sealant is a gray water-based duct sealant used in medium and high-pressure duct systems. It is a special formulation which is non-flammable and provides permanent flexibility, excellent water-resistance and superior sealing strength. Use it to seal metal to metal joints to prevent air leaks in medium and high pressure systems of spiral and rectangular ductwork for air-conditioning, refrigeration, ventilation, and air distribution. RD•DS 181 may also be used to seal joints on run-outs of connecting metal flexible tubing. Cured sealant is discoloration resistant. Made in USA. Red Devil, is still a privately-owned family business with state-of-the-art manufacturing facilities in Pryor, Oklahoma. Click on the Red Devil link at the top of this page to visit our Brand Store.