The tray is completely disposable for hands-off convenience. It is pre-filled with Premium Blue litter, which has been proven to provide unbeatable odor control. You don?t have to see, touch, or smell messy waste. Simply replace the disposable tray every few weeks, and your ScoopFree litter box is just like new. These trays work with ScoopFree self-cleaning litter boxes and ScoopFree Slide. Features: Includes Premium Blue Crystals litter that stops odor 5 times better than clay and clumping litter Completely disposable, so you don?t have to see, touch, or smell messy waste Covered waste trap locks in odor and leaves litter smelling clean and fresh Plastic lining creates a powerful barrier to help protect against leakage Crystal litter doesn?t clog rake or clump to the bottom of the tray Safe for all cats Weighs only 6.5 pounds (includes 4.5 pounds of litter) Litter is low tracking and 99% dust free. Absorbs urine on contact and dries solid waste to reduce odor. Uses 5 to 10 times less than clay and clumping litter, so there?s less to buy and bring home. We recommend replacing the litter tray at least once every 20-30 days for one cat, every 10-15 days for 2 cats, every 7-10 days for 3 cats. Tip: ScoopFree litter trays can be used by themselves as disposable litter boxes. When used this way, either scoop the waste under the waste trap flap or remove entirely as often as needed. Mixing the litter daily is also recommended. When the tray is ready to be disposed, simply cover it and toss it in the trash. Product Specs: Litter tray measures 14-1/2? wide by 22? long by 2-1/2? high Weighs 6.5 pounds Patents pending *Kittens less than 6 months old may experience a shortened litter tray life span. Kittens may also have softer stool than mature cats, which increases the likelihood that it may stick to the rake. Cats who consume a diet high in crude fiber, ash and byproducts may experience a shortened litter tray life span. Cats over 10 years and cats with health problems may also experience a shortened tray life.