10 OZ, Black, Fireplace Repair Mortar, Silicate Based Refractory Cement Caulk Is Used To Tuck Point Damaged Fireplace Mortar Joints & Repair Cracked Or Chipped Firebricks In Fireplaces & Wood Burning Stoves, Provides Superior Adhesion & Withstands Temperatures Of 2,000 Degrees Fahrenheit Or 1,093 Degrees Celsius, Heat Cured Within 30 Days.