Furnace humidifier filter. Improve humidification with a new replacement pad. Materials and workmanship equal manufacturer specifications. Fits Aprilaire 110, 250, 500, 500A, 558, CHIPPEWA 220. Fits Honeywell HE220A, 220B, 225A, 225B. Fits BestAir BA3022G. Fits Lasko 5000L, 5000EC, 6000. Fits Hamilton 12HF. Fits Lennox WB212.