KOS Flue Cement is a high temperature (to 1,250C) ready mixed fireproof mortar paste, designed for the safe installation/jointing of Type A1 (BSEN1857) concrete flue liners (previously known as class 1) for use with domestic fires and stoves e.g. coal, wood-burning or gas (including flame effect). KOS FLUE CEMENT may also be used as a general-purpose fire cement in most applications where direct flame contact occurs.