10.3 OZ, Buff & Mortar Cartridge, Especially Suited For Repairing Cracked & Chipped Firebrick & Tuck Pointing Mortar Into Damaged Masonry To Masonry Joints, Durable As Firebrick When Heat Cured, Withstands Temperatures Up 1,093 Degrees Centimeter, 2,000 Degrees Fahrenheit, Meets A Tm136-79 Flammability Test.