Chimney Master Round Poly and Wire Heavy Duty 3/8" NPT Chimney Cleaning Kits

To determine the size brush you need just measure the inside diameter of the pipe and select the same size brush - if your pipe has a 6" inside diameter order the 6" brush which is actually about 6 1/4" in diameter which has a slight flex assuring a correct fit for efficient cleaning. Use a poly brush for cleaning metal flues and a wire brush for cleaning masonry flues.