The Latex-ite Pli-Stix 30 ft. Driveway Crack and Joint Filler - Medium Black is a contractor-grade thermo-plastic rubber that's designed for use with a heat gun or propane torch. It is a permanent, soft-bonding, self-leveling seal for concrete, asphalt, and expansion joints that's 100% watertight and traffic-ready in 20 minutes.