Supreme silicone window and door sealant is a premium, 100% silicone and 100% water-proof sealant that provides a reliable seal in weather prone areas like windows, doors, basements, roofs, sidewalks, siding, tuckpointing and attics. This sealant offers 100% more flexibility than Class 25 sealants and 7X stronger adhesion than Silicone 1® sealant. And, it offers 50% joint movement capability without cracking, shrinking, breaking down or washing away. This sealant has lifetime mold-free product protection that resists stain causing mold and mildew growth.