About this item Night-Optimized Silent Runner: Upgraded aluminum dual-ball bearings operate 60% quieter than plastic, perfect for nocturnal pets. Designed for place on the platform for mounting to enhance noise reduction through vibration absorption, ensuring peaceful nights. Stress-Free Deep Cleaning: Fully detachable rust-proof core pairs with water washable-safe acrylic body for effortless maintenance. Pro tip: Always air-dry bearings separately after cleaning for lasting smoothness. Energetic Pet-Proof Stability: 30mm reinforced base with shock-absorbing grooves prevents wobbling during marathon runs. Optimize performance by securing the included platform on flat surfaces for dwarf(21cm) and Syrian(26cm) sprinters. Terrain-Smart Safety Runway: Preserved 12° M-shape slope mimics natural terrain, preventing falls with wider surface accommodates clumsy pups and senior pets.Best for the small animals like: Roborovski hamsters, Campbell hamsters, Chinese hamsters, Dwarf Hamster, Lemmings, mice, or tiny Gerbils, Syrian Hamsters (Teddy Bear Hamsters, Golden Bear Hamsters), Gerbils. Universal Cage Compatibility: Tool-free 9″ (ca. 23cm) to 12.2″(ca. 31cm) height adjustment adapts to any habitat. Centrally position the platform-mounted wheel for Roborovski/Syrian/Gerbils without cage modifications. Size options are based on your hamster’s type and the cage’s size. If the diameter of the running wheels is too small, it will affect the spine. That’s why we recommend the larger hamster wheel. See more product details