Bionaire Litter Box REPLACEMENT FILTERS by Oster Jarden -4 sets of filters Description: FOUR sets of replacement Pre-Filters and Odor Filters for the revolutionary Bionaire Odor Grabber Litter Box. The Bionaire Odor Grabber Litter Box automatically removes litter box odors while sending fresh, odor-free air into the room. THESE FILTERS SHOULD LAST APPROXIMATELY 6 MONTHS Jarden