FLEX SEAL LIQUID ® is liquid rubber, in a can! Unlike traditional paints, Flex Seal Liquid starts out as a thick liquid, that can seep into cracks and holes to form a waterproof, weatherproof seal. Easy to use, just brush, roll dip or pour to stop leaks fast. Flex Seal 128-fl oz Black Pour Waterproof Rubberized Coating | US855BLK01