OSI, 10 OZ, RF140, Black, Roof & Flashing Sealant, Manufactured With A Special Synthetic Rubber & Select Cuts Of Asphalts, Cures Into A Tough, Rubbery Film With Greater Expansion & Contraction Flexibility, Resists Cracking, Enhanced Adhesion, Can Be Applied At Temperatures Between 20 Degrees & 90 Degrees Without Extrusion Difficulty.