[Environmental material]: Hamster fitness balls use high quality environmentally friendly plastic materials that protect the health of pets. It is made ; new PC material with lock design, easy to install, convenient! [Hollow runner]: The hollow design on both sides of the runner makes the runner more breathable and allows the hamster to do aerobic exercises. There are several safe and breathable ventilation holes on the ball, your little pets can play for a long time! 【Transparent balls】: Pets can play large transparent hamster balls, and the owner can hold ; animal. so beautiful! [Easy to install]: With interlocking design, slight pressure can be formed, easy to install! [DIY combination toys]: This little rat hun can do with the external whistle and ; unlimited expansion, let you do the DIY combo to add to the ; animal problems! Number: 1 piece of