Designed from top to bottom for easy litter management, Catit Airsift Hooded Litter Boxes provide your cat with optimal comfort and privacy. The litter boxes are easy to set up and provide wide access for scooping and cleaning. The included Catit Airsift filter pad, safely tucked away in the top compartment, helps control litter box odors in a cat-friendly manner.The Catit Airsift filters absorb odors instead of masking them with fragrant, chemical scents. Ammonia smells and other nasty odors are reduced so your cat can breathe freely while doing their business. The Litter Boxes with Airsift Filter System include one Airsift pad. Airsift filters are available in 2 or 6 packs. Change pad every 30 days for best results.