Rowdy, escape-artist dog can't bend the bars of this one, but he has managed to escape, even with the little "hook" provided to make opening the cage harder. It was very easy to put together. I was able to do it by myself in about 15-20 minutes. Not sure I'm entirely crazy about the wired bottom. (See previous mention of dog who bends metal easily.) I really like the flip-open top - makes it easy to give pup a bone or some toy. I'm going to have to come up with a better way to secure the door to deal with my escape-artist pup! We opted not to add the castors right now, so that's a nice option. Our dog is a 65 lb Catahoula Leopard Dog mix, and he has good room in it. Overall, I'd recommend it.