š¹ćPackage Includedć12.5cm. Tunnel diameter: 5.5cm, suitable for hamsters, ferrets and guinea pigs and small pet. Our hamster cage tubes kit has 16pcs hamster tubes, 2pcs external pipe connection plates, 2pcs hamster tube cap and 1pcs hamster wheel. No Smell, sturdy and not easy to wear and corrosion.Well protect the health of pets. š¹ćTransparent and Stylish Designć The transparent design will make it easy to observe your pet hamster exercising, and curious pets will be drawn to the fun tunnel. You can play with your pet and satisfy your pet's natural instincts to add even more fun. š¹ćSafe and Friendlyć The hamster tube set is made of hard plastic to prevent pets from biting. With multiple ventilation holes and an uneven inner surface for increased friction and air circulation, pets will not get hot or find it difficult to breathe when staying inside for long periods of time, making it conducive to pet play and durable. š¹ćEasy to Installć The clear tunnel can be easily spliced and disassembled, no other tools are required, and the hamster ball adopting the lock design, can be molded with a light press. When the installation is performed, the position of the dark buckle of the cover is aligned with the corresponding position of the running ball. š¹ćWidely Applicationć The hamster toy cage accessories are suitable for providing more activity space for small pets. You can mix and match the outer track at will, and several groups can be spliced together to connect the hamster bathroom of the same diameter and you can also use them to expand the space outside the cage to bring more fun and exercise to your small pets. š¹ćConnectable & Expandableć The hamster cage tunnels kit are expandable and designed to connect to other habitats, provide an unlimited amount of living space for your pet hamster, gerbil, or mouse. š¹ćEenvironmentally Friendly Materialć The clear hamster tube kits are made of high quality PC material, Safe, No Smell, Durable and Non-toxic, Environmentally Friendly and Easy to clean. š¹ćKeep Healthy and Breathableć The hamster tube and runner ball has multiple ventilation holes which are safe and breathable for your little pet to play in!