We got into the rod making business after we started making cameras. We found that rods that screw together are great for sweeping, but when you add the weight of the camera the rods can "un-screw" and then they and the camera come crashing down the chimney. This is why we suggest that if you buy a Chim-Scan® that you have "locking" rods.
Our Kwick Lock™ Rods, Caddies and Kits are made in the U.S. at our location. We make sure that every rod will do it's job well. We use a modified air hose fitting for our rods, they're easy to put together and they 'lock' so that they wouldn't come apart in the chimney.