Metal-Fab 6Tgg48 6"x48" Temp/Guard 2100 Chimney. This Metal-Fab 2100 Chimney is a genuine part manufactured by Metal-Fab. This Temp GuardÂ® chimney is intended for use on residential and building heating appliances burning wood, oil, coal, or gas. Temp GuardÂ® is tested and listed to UL standard 103HT. The maximum continuous operating temperature for this product is 1000Âº F.