PetSafe.net: PetSafe® ScoopFree® is the original self-cleaning litter box and continues to be the world's bestselling automatic litter box. PetSafe&rsquo;s newest automatic litter box is now compatible with clumping litter welcoming more cat owners into the ScoopFree® family. ScoopFree® Clumping is affordable ($279.95) compared to other self-cleaning litter boxes in the marketplace & is the only 21-day hands-free automatic litter box.