I also modified a bit. I couldn't find any PVC or cardboard that was 6" or more in diameter and already cut down to a reasonable length. I cleaned an old coffee can extremely well, used a can opener to take off the bottom, made sure the whole edge was very smooth, and then covered it with my fleece as explained previously. I did not attach it to the cage with the hardware described, but instead I stretched a long scrap of fleece into a sturdy string (like a 1" thick strip of fleece pulled tight) and ran it through the inside of the fleece tube. I could have tied that to the cage on both sides of the tube, but I tied the ends to clips that attach to the cage. So, the fleece removes easily, it easily unclips, is still sturdy, is easily moved, and I didn't have to drill any holes or buy any hardware.