The Kaytee Comfort Wheel features a safe, solid running surface, quiet operation and a "tail-safe" design, allowing pets easy entrance and exit. Every Comfort Wheel comes with a heavy duty wire stand and a 2-way attachment clip, so the wheel can be used either free-standing or clipped to a wire cage. Heavy duty wire stand lets you use it as a free-standing wheel, or you can attach it to a wire cage with the two-way clip. Designed for quiet spinning Features a safe running surface with a "tail-safe" design Encourages safe and healthy exercise Available in assorted colours *Colour shipped will vary* Available Sizes: Large 8.5" diameter (recommended size for smaller hamsters, gerbils, mice) Giant 12" diameter (recommended size for syrian hamsters, gerbils, mice, sugar gliders, smaller hedgehogs, smaller rats, smaller degus)