StopGap Acoustical Sealant is a highly elastic, water-based sealant used for reducing sound transmission. It works at the perimeter of wall systems or around electrical box cutouts to achieve specified STC/MTC values. The surface dries to a tough film but the sealant remains flexible and stays pliable up to five times longer than alternative brands. And, unlike other products, Auralex StopGap has no residual run-off. StopGap is paintable and non-staining, and meets ASTM C-834 standards for flame retardancy.

StopGap comes in a large, 29 oz caulking tube and therefore requires a larger-than-normal-sized caulking gun, which can be purchased at any local hardware store. Coverage per 29 oz cartridge is approximately 40 linear feet when a 3/8" bead is applied.