Cey never liked his nylon airline carry-on crate. It's a bit too small for him I think (even though it's supposed to be up to 20 lbs or something). On the other hand, he loves loves loves his metal wire pet crate, which he's had since I brought him home. I just put a fleece blanket on the bottom and a small cover draped over the top and keep the door open, and he crawls right in if he is tired and I am not in my bed to snuggle with

. I use it to contain him on the few occasions that I need him contained and he doesn't mind a bit. In fact, he is so possessive of his crate that he sort of freaks out if anybody messes with it, including packing it up for taking a trip haha.
It's not very big, and it folds up if necessary. It wouldn't work for airplane travel of course but I take it whenever we sleep over at somebody else's house and it fits great in my car even without being folded

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Oh, and it comes with a divider so that the inside size can be adjusted when your dog is a puppy. Best dog thing I have ever bought!