Super Pet's Small Comfort Wheel Is Perfectly Sized For Your Healthy Hamster, Motivated Mouse, Or Jogging Gerbil. The 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