Honeywell Air Purifier Enhanced Filter Series is designed to help reduce the most common household odours and VOCs, so you can customize your filtration experience based on your needs. Four (4) options are available in this line: Pet, Smoke, Kitchen, and Home Renovation. This OEM genuine Honeywell HRFSP1V1 Enhanced Pet Odour Air Purifier Filter “S” is specially formulated with activated carbon and zeolite to help capture and absorb pet odours. Use of this filter along with the Pre-Filter and HEPA Filter may help reduce pet odours up to 3.5 times faster (1).