HDX Window and Door Silicone is a 100% silicone rubber sealant that is ideal for sealing cracks and gaps around windows doors, plumbing openings, vents and ducts. It provides a watertight flexible seal that is resistant to sunlight, rain, snow and extreme temperatures. Cured bead will not crack, crumble or shrink and adheres to most wood, metal, vinyl siding, drywall/plaster, glass and painted surfaces. It is designed to be used on windows, doors, siding, trim, gutters and molding. Once cured, it is unaffected by temperature extremes (-60 degrees Fahrenheit to 400 degrees Fahrenheit).