Each ScoopFree Crystal Disposable Litter Tray is pre-filled with crystal litter so all you have to do is load the tray in the litter box with no scooping, cleaning or refilling for weeks! These trays reduce mess in your home with a plastic lining to fight leaks, and with low-tracking crystals that stick inside the box instead of on your cats paws. Crystal litter absorbs urine and dries solid waste to quickly remove odors 5 times better than clumping clay litter. When it's time to clean up, just remove the disposable litter tray and throw it away. It doesn't get much easier than that! These replacement trays are compatible with ScoopFree Crystal self-cleaning cat litter boxes. Your pet deserves the best. Trust PetSafe to help keep your pet healthy, safe and happy.