Durable & Cute Decor - Made with 3mm thickness AS plastic (Running Drum) & 8mm thickness Acrylic (Base of hamster wheel), chewing-resistance, sturdy Design that achieves reliable standing & support when running or walking. 4 colors in choice bring more beauty viewing to hamster cage decors, and easily matches multi styles of cage themes. Super Silent Hamster Exercise Wheel- designed with Al alloy dual ball bearings and high precision axis to ensure the wheel glides smoothly and silently. The bearings SPIN around the bolt as your pet runs reducing friction and noise during running. Allows your animals to run comfortably and happily without noise at night. (Ball bearing can not be soaked into the water directly). Safety & Easy to Use - The integrated gentle slope running wheel can buffer and slow down, also the running track is continuous without cracks or tripping problems, avoiding being thrown away and reducing the risk of fur/tail entanglement, pet wrap-a-round and other injuries. The running drum can be disassembled for water washability. Adjustable Height & Stable Experience-Adopt a 30mm Back Acrylic pillar as the main support for maximum protection against rebound and deflection during exercise. Variable height is between 13.1" (ca. 33.5cm) to18.4"(ca. 47cm) bottom height, you can adjust the height of the hamster wheel's running drum to fit the species of pets you cared for or the size of the cage you used. Different Size of Hamster Wheel-Running Wheel Outer Dia is 32cm/12.5" and the Width of the runway is 11cm/4.3". Stand size is 29 x 17.5cm/11.4" x 6.9" (L*H). It's recommended for most Syrian Hamster, Sugar Gliders, Degus, Rats, Hedgehogs. We designed 2 sizes with different Dia. to provide a back-friendly running experience to hamsters of various species and sizes, please choose the right one for your pets.