The Kaytee Critter Cruiser Small Animal Exercise Wheel is an exciting pet-powered exercise car that encourages healthy exercise. This interactive toy is great for pet hamsters, gerbils, mice and other small animals. The adjustable racing wheel gives your pet three different fun ways to use the wheel. With the Comfort Wheel in the top position, critters can spin the wheel and the cruiser remains stationary. When you move it to the middle position, you can watch your pet turn the wheel and roll the car on any flat surface. In the lowest position, the Critter Cruiser works directly on Super Pet’s Hamtrac.