[Large play area]: The outer pipe allows more space to extend the cage, giving the pet more room to move. The inner diameter of the pipe is approximately 5.5 cm. Please measure the required size before placing an order, to give your pet a suitable and comfortable gym. [Excellent Animal Exercise Room Set]: The pipe set includes one long straight pipe, two short straight pipes, one T-pipe, four separate bent pipes, a total of 8 sections. Ideal for hamsters, gerbils or mouse cages. [Improved Material]: Hamster hoses are made of high density plastic, sturdy but relatively easy to disassemble / change. Easy to clean. Perfect hamster toy, record every charming moment. [Easy to use]: a very simple set of pipes. You can create a new exercise room for your adorable pet without instructions. Transparent shell lets you know the appearance of its movement more clearly.