Flex Seal Liquid is a thick, liquid rubber sealant coating that dries to a durable, flexible, watertight barrier. Ideal for sealing leaks, cracks, and holes, it can be brushed, rolled, dipped, or poured onto surfaces such as roofs, gutters, foundations, RVs, concrete, metal, wood, and more. The clear formula provides long-lasting protection against water, air, and moisture.