Material Safety: The Hamster Running Wheel Made of premium PP material, have thick walls and rounded edges. non-toxic and tasteless, can use a long shelf life. it is healthy and harmless to your pets. the diameter of the rollers is 12/14cm. Anti-slip convex lines: The Pet Hamster roller toy has non-slip convex lines, increase friction and improve stability, avoiding stepsthe errors The cage casters has a diameter of 14cm and is easy to install. It can be easily mounted on the side of the cage or placed inside the cage using the stand. Easy to Clean: The Hamster Exercise Wheel Toy Adopt a transparent and fully open design, it is useful for deep cleaning as there are no corners to hide the droppings. Wide applications: This The racing wheel is designed for hamsters, gerbils, hedgehogs, mice and more similar small animals. It allows these animals to be entertained and exercised, to stay in shape and to stay happy and healthy. All Products From Us Have Undergone Strict Quality Checks. if There Is Any Quality Problem Or You Are Not Satisfied With The Product contact Us. we Will Give You The Best Solution.