With the 8 inch by 12 inch Rectangular Master Sweep Flat Wire Brush Head with TLC Torque Lock Connector you have a brush that has been engineered to last for a very long time giving to you the highest quality of cleaning possible. Master Sweep chimney brush head with an 8-inch x 12-inch rectangular shape. Features the newer TLC-style torque lock connector. Tough durable flat wire bristles are used to score glazed creosote before applying a creosote removal solution (purchased separately). Master Sweep flat wire brushes are made for top-down sweeping from the roof. Brush head wont spring back to its original shape if it is jammed past a damper frame. Brush head has a has a heavy-duty double spiral 0.177 dia. spindle design. The seven inches of fill is two on two high density oil tempered 22 gauge 0.0286-inch wire bristles creating uniform rugged bristle distribution. Master Sweep brush heads are long-lasting professional brushes that withstand the demanding abuse encountered by busy commercial chimney sweeps. Cleans chimneys more thoroughly and outlasts many comparably priced brush heads.