Permatex Copper Spray-A-Gasket Hi-Tempt Adhesive Sealant is a fast-drying, metallic copper sealant that helps dissipate heat, prevents gasket burnout and improves heat transfer. Fills minor surface irregularities. Seals instantly. Fills hot spots and surface imperfections. Temperature range -50 degrees Fahrenheit to 500 degrees Fahrenheit. Resists all types of shop fluids, especially gasoline. Level 3 and up.