We got our two cats one of these wheels our youngest cat Zeus loves it and can be heard running on it at two in the morning our older cat Komere has never bothered much with it but she likes to sit in it
I volunteer at a cat shelter We have wheels in each room We have The Cat Wheel It has a back on it. I am not sure of the cost The cats LOVE it. It can be a little loud when the cat gets going. It has "grips" on the inside and is very sturdy. They are used constantly and hold up well Hope this gelps
I have been thinking of buying one for Charlie, but have been hesitant as I don't want to spend the money if he would never run in it. How long did it take for your cats to get accustomed to the wheel?