wood-burning fireplaces normally have a damper and a flue liner or a metal box with a round metal chimney pipe that's at least 8 inches in diameter. If you're still not sure,consult a professionalchimney expert or gas expert.
You will need flexible fiberglass rods to attach to the brush. So, check the overall height of the chimney. If a measuring tape cannot be used, simply drop a rope from the top of the chimney, through any offsets and down through the damper and into the fireplace. Then, simply measure ...