100% silicone sealant for building and repairing aquariums. Sealant stays flexible and will not crack or shrink. Nontoxic to fresh and saltwater fish when cured. Tack free in one hour and is fully cured and bonded in approximately 24 hours. Adheres to most surfaces including glass, nonoily woods, metal, porcelain, ceramic, painted surfaces, many plastics and rubbers. Packaged in a 2.8 fl. oz. squeeze tube.