Filter-Monster branded carbon replacement compatible with Honeywell Filter K (HRF-K2). Reduces household odors from cooking, cleaning and smoking. Captures larger particles before reaching filter, extending life of filter. Designed to fit Honeywell air purifiers in the HFD120Q and HFD300 series including HFD-120, HFD-120Q, HFD-300, HFD-310, HFD-320, HFD-323. Recommended to replace every three (3) months for maximum effiiciency, or more often in harsh environments. Package contains two (2) pre-filters. Filter-Monster branded carbon replacement compatible with Honeywell Filter K (HRF-K2). Reduces household odors from cooking, cleaning and smoking. Captures larger particles before reaching filter, extending life of filter. Designed to fit Honeywell air purifiers in the HFD120Q and HFD300 series including HFD-120, HFD-120Q, HFD-300, HFD-310, HFD-320, HFD-323. Recommended to replace every three (3) months for maximum effiiciency, or more often in harsh environments. Package contains two (2) pre-filters.