Kaytee's Critter Cruiser is a pet-powered exercise car perfect for hamsters, gerbils, mice, and rats. This amazing product has an adjustable racing wheel that allows the car to function in three different ways. When the Comfort Wheel is in it's top position, the Cruiser remains stationary. In it's mid position, the Cruiser is mobile and you can watch your pet roll around any flat surface. Finally, when the wheel is in it's lowest position, the Critter Cruiser works directly on Kaytee's Hamtrac. Not only does this product encourage healthy exercise in a safe and secure way, it also makes a great holding area to keep your furry friend as you clean their home.