The JUILE YUAN Silent Hamster Wheel is a safe and easy way to exercise your small pets. Made of stainless steel ball bearings, it slides smoothly and quietly on any surface. The shaftless design eliminates the dangerous center rod, reducing the risk of fur / tail entanglement. The wheel is also easy to clean with a transparent design that allows for deep cleaning. With a 7 inch diameter, it’s perfect for use in any home or office.