Review on 🐹 PINVNBY Hamster Fun Tunnels Pet Mouse Plastic Tube Toys Small Animal Foldable Exercising Training Hideout Tunnels for Guinea Pigs, Gerbils, Rats, Mice, Ferrets and Other Small Animals - 2 PCS Blue by Dana Wood

My black bear loves whistling. It's a bit heavy so smaller tubes won't fit. I haven't had to clean them yet (he's pretty much litter box trained) so can't say for sure. Someone said they were too loud. They open and close a little noisily, but the mechanism works in such a way that they can be removed. It doesn't bother me much. It is worth it because of the space-saving quality. They are a bit thin so you have to be careful not to bend them wrong when closing them. But really, it was the best deal I've seen and they do the job.