WindowWrap Flex PowerBond is a flexible, 70-mil waterproofing tape that is designed for use around curved window and door openings, as well as sealing building joints. The exclusive, patented PowerBond adhesive system allows the product to aggressively adhere in temperatures as low as 25°F (-4°C), while remaining stable at elevated temperatures. Excellent for use in waterproofing window sills. The polyethylene crepe film allows the product to stretch to conform to any irregular shape. White color. May be left exposed for 90 days. Impermeable to water vapor, moisture, insect and air penetration. Backed by a 15-Year warranty.