This is the best chimney sweep you will find. My chimney is 28' long and roof is 9/12 pitch. Before this, I had to get on the roof, take off the top 4" of chimney, sweep it from above and reinstall the chimney. Now, I can do it from inside the house. I made a plywood door for the stove that I put on after I have the sweep inserted (to capture the dust from getting inside my house), turn the drill on and push it up to the top of the chimney. This is the best design I've ever seen, it is so flexible and strong. Do yourself a favor and buy this now. So much better than any other sweep I've seen or used.