actually got a video to work on youtube, built a cat-tree for my cat, he is too fat to fit through the opening, watch him trying, LOL https://www.youtube.com/watch?v=fXZBnHMAu04
LOL i know! it was from the store, a good price, you just have to assemble it yourself, it took us forever, but the payoff was worth it!
well.. if he keeps struggling that much to get through that hole it'll burn a few calories and slim him down.. my friend had a cat that was so fat i couldn't put my arm all the way around it!