This smartly designed unit features two nesting pans and a sifting screen. Stack the pans with the sifting screen on top and fill with clumping litter. When you lift the sifting screen the litter sifts out into the pan, leaving the clumps that you throw away. Replace the sifting screen in the empty pan, move the litter from the full to the empty pan, restack, and your are finished. Made of durable, easy to clean plastic.