CoolFun design keeps pets entertained and enriches their environment by providing new and different places to play and hide.Compatible & ConnectableUniversally connects to all CritterTrail, Habitrail, and S.A.M. systems.ColorfulHas fun colors kids love and dark translucent colors for your critter's comfort. Includes:1-Loop-D-Loop1- Fun-nel J-Tube1- Bubble Plug1- Fun-nel U-Turn2 Fun-nel Elbows4- 3.5" Tubes6 Connector RingsStart Collecting and Connecting Today