*** (This item sold as a pack of 12) *** Formulated to create a long lasting watertight and weatherproof seal with superior flexibility and adhesion to a variety of building materials. When cured, it is mold and mildew resistant and will not crack or shrink. Unlike acetoxy silicone sealants. This premium silicone rubber window and door sealant is low in odor. Meets ASTM Specification C 920, Class 25, Type S, Grade NS. 10.1 fl. oz. cartridge.