Fun-nel Tubes are the ideal way to expand your CritterTrail habitat. Easy to connect and pull apart so you can add space for more roaming area in minutes. The Bubble Wave tube design features a comfortable grip that is safe for your pet's paws. Connector Rings snap on easily to ensure a safe and secure passageway. Easy to clean, tubes pull apart and snap back together for trouble-free cleaning. Buy any of our wide assortment of Fun-nel tubes and accessories to create your own unique habitat for your pet. Universally connectable and come in assorted colors.From the Manufacturer:CritterTrail is a connectable & expandable system designed to grow with your pet. We suggest you start with a habitat that has everything you need to make your pet feel right at home. Each of our CritterTrail Habitats includes a food dish, water bottle, and exercise wheel. All CritterTrail habitats are expandable and designed to connect to other CritterTrail habitats and fun-nel tube accessories, creating an unlimited amount of living space for your pet hamster, gerbil, or mouse.