For quick, permanent repairs to leaks in all types of plastic tanks including coolant or windshield washer reservoirs, and radiator overflow, water, or waste tanks. Repairs cracks up to 4" long and holes up to 3/8" diameter for cars, trucks, boats and RVs. Complete kit includes everything needed for repair and easy-to-follow instructions. Fast curing, can make repairs in 30 minutes. Not for use on fuel tanks.