Arm and Hammer Electrostatic Air Filters (4 Pack) Unscented odor fighting power of Pet Fresh. Technology aimed at managing pet and other common household odors is incorporated into the filter. Captures particles like pollen, dust, pet dander and a variety of other common airborne allergens. Filter last up to 90 days. The ARM & HAMMER name, logo, distinctive orange trade dress and PET FRESH are trademarks of Church & Dwight Co., Inc.