The Kaytee CritterTrail Fun-Nels Tube 4Way Cross is a great way to add some extra fun to your life with your furry little friends. This tube is made of plastic that is safe for your pets, and it comes in assorted colors so you can find the perfect shade to match your home dcor. The tube is easy to use, and it comes with a connector ring that makes it easy to connect to other tubes and accessories. Each tube has ventilation holes for your safety, and the 2.25″ diameter makes it easy to feed your pet.