The Catit Airsift Dual Action Odour Reducing Pad is Catit's best-performing filter pad, combining two cat-friendly media: powerful Magic Blue Ammonia Buster, plus activated carbon to keep nasty smells at bay. Helps to reduce unpleasant litter box odours Include Catit Magic Blue Ammonia Buster PLUS activated carbon for higher efficacy For use in Catit litter boxes with Airsift filter system One filter pad lasts for 30 days Size: 2 Pack