Ware Manufacturing Critter Universe Universal Small Pet Tunnel, 3-Pack Small pet critter universe universal tunnel Easy to climb contour design Unique flexible design Compatible with critter universe and other brands Measures 2-1/2-inch width by 2-1/2-inch derby 8-inch height Critter Universe Fun Tunnel Your Small Pets Will Love to Crawl Through Easy to Climb Contour Design, Gives Great Traction Connect Directly to Cage or Connect End to End Compatible with Other Brand Connectable Systems, Expandable Easy to Clean, Simply Just Wash Off Measures 2-1/2" Width X 2-1/2" Derby 8" Height