** DO NOT USE THIS THIMBLE IN OR AROUND COMBUSTIBLE MATERIALS. BRICK AND MORTAR ONLY **
Use this galvanized fireplace wall thimble as a sleeve when running stovepipe through the side of a masonry chimney. Keep its inner end flush with the inside of the flue surface. The thimble is 12" long and meets NFPA 211 standards sizes for 6" or 8" application, and cuts easily.Inside dimensions are 8 3/16" .