Kaytee Hamtrac Exercise Loop. Kaytee Exercise Loop will have your pet running in circles! This racetrack provides interactive fun for both you and your pet! Place your pet's Run-about Ball or other exercise toy onto the track and watch as they race 'round and 'round! The Exercise Loop provides a safe way to always know where your pet is while encouraging necessary exercise. Exercise Loop provides interactive fun for you and your pet Makes a great temporary holding area to keep your furry friend while you clean their home Ideal for hamsters and other small animals For use with any Super Pet Run About Exercise Ball Assembled size 25-inch diameter. Run-about ball NOT included. 18" x 8.5" x 2.5"