Flex Seal Flood Protection is designed to help prevent damaging flood waters from entering people's homes and businesses. Should be used in combination with our other Flood Protection products. Use on all types of openings such as windows, doors, seams, garages, casings, thresholds, conduits, vents and ducts, key holes and more. Verified by UL for No water penetration through 1/8" gaps at depths up to 3 feet, for 14 days. Use as a final coat of protection to help seal any small pinholes or openings that may have been missed.