High Quality Material: Our hamster tube set is made of hard plastic to prevent pets from biting it. Rugged inner surface, good for climbing, long lasting and more fun.Connectable & Expandable: The hamster cage tubes kit are expandable and designed to connect to other habitats, provide an unlimited amount of living space for your pet hamster, gerbil, or mouse.Infinite Fun: Curious pets will be attracted to interesting tunnels, which will enhance increase your pets quality of life and bring even more interesting and entertaining venues in which hamsters can explore, exercise and simply chill out. Satisfy your pet's natural instincts.Safe & Friendly: There is no gap in the hamster tunnel connection, the pet's paws will not be caught and hurt. They are easy to assemble with hands and you can splice as you like. No glue/nails/screws needed, very user friendly!Size & Package: Tunnel diameter: 2.1inch, great for Hamsters, ferrets and rats, guinea pigs and small pet. Our hamster cage tubes kit is consist of totally 8pcs and they can be spliced together to connect the hamster bathroom of the same diameter.