Each ScoopFree disposable Crystal Litter Tray is pre-filled with premium blue crystal cat 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 cat's paws. Crystal litter absorbs urine and dries solid waste to quickly remove odors 5 times faster 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 self-cleaning cat litter boxes. Your pet deserves the best. Trust PetSafe to help keep your pet healthy, safe and happy.Tips for Maximizing the Life of Your Crystal Litter Trays 1. Place the ScoopFree Crystal litter box away from areas of high humidity, such as bathrooms, showers, and basements. Since the crystal litter controls odor by absorbing moisture, having extra moisture in the air will shorten the life of the tray. Try placing it in a room with moving air to pull away moisture, like a room with a fan. 2. If your cat consistently urinates in the same spot, try stirring the crystals occasionally to help distribute saturated crystals. 3. Cats with diets that are high in crude fiber and ash content will produce more solid waste, which can prematurely fill the waste trap. Consider changing your cat's diet to a food with no byproducts or fillers.