Kaytee CritterTrail Fun Twist and Turn Value Pack, Colors Vary Allows for expansion of CritterTrail habitats Includes: 2 - Tee Tubes, 1 - U-Turn Tube, 2 - Elbow Tubes, 6 - Connector Rings Universally connectable 2.25" diameter and a variety of shapes and lengths For hamsters, gerbils or mice