Rutland Round Professionals Choice Polypropylene Brush Head With Tlc Torque Lock Connector (7" Diameter) Professionals Choice round chimney brush head with a 7-inch overall diameter. Features the newer TLC-style torque lock connector. Polypropylene bristles are designed for removing soot from fossil fuels in coal&#44; oil or gas flues Brush head has a has a single spiral 0.177 dia. spindle design. The 0.075-inch poly filaments are 7 inches of fill.