I have a straight 8\" stainless steel chimney flue that comes down into my house and makes a 90° horizontal turn into the back of a wood stove. I used to clean the chimney from the top using rigid steel rods and a very firm brush. For whatever reason I could not find them this season and ordered this product. The rods themselves are probably at least half inch in diameter, but still quite flexible. They snap together quite firmly without needing a set screw. In fact, you'll need to use the little tool that comes with the kit, a nail or small screwdriver to push the little pin to get them to release. This tool allowed me to clean my chimney flue from inside the house for the first time, which is safer than climbing on the roof and straddling the top of my chimney. The whole thing breaks down and fits nicely inside of a nylon drawstring bag that I'm going to hang inside of my garage (where I can find it next year 😏) Good price. Five stars and I would definitely recommend.