ScoopFree is a revolutionary automatic litter box that uses disposable no-mess litter cartridges, pre-loaded with Fresh Step brand crystals. You simply replace the cartridge about once a month for each cat. That's it!90-Day Guarantee: If you are not satisfied with your Scoop Free within 90 days of purchase just send it back to us for a product cost refund (shipping is non-refundable) Includes One Cartridge Using FreshStep Odor-Absorbing Crystals Self-cleaning litter box measures 19 wide by 27-3/8 long by 7 high Litter tray measures 14-1/2 wide by 22 long by 2-1/2 high UL Rated Power Supply Fill And Leave For Up To 30 Days! No Mess To Touch Changing Cartridges Is Fast And Easy Unbeatable Odor Control Recommended litter tray replacements*: At least once every 20-30 days for one cat, every 10-15 days for 2 cats, every 7-10 days for 3 cats Cats love ScoopFree because it keeps their litter box clean and fresh. Cat owners love ScoopFree because there is nothing messy to see or touch. Fresh Step Crystal litter offers unbeatable odor control and the Scoop Free automatic litter box provides superior convenience.