[Compatible Model] HFT600 humidifier wicking filters are specifically designed to fit for , HEV615 Series, HEV620 Series: HEV615, HEV615B, HEV615W, HEV620, HEV620B, HEV620W, HEV-615, HEV-615B, HEV-615W, HEV-620, HEV-620B, HEV-620W, Compare to part # HFT600T & HFT600PDQ. [Materials & Performance] The environmental protection professional filter paper has a diamond-shaped grid structure which allows for maximum absorption of water for Best moisture output and increase the humidity in the dry season and create a comfortable home environment . [Exchange ] About 1-2 months (depending on use and local water quality), Before replacement, soak the wick of the HFT600 filter in water to uninterrupted water output. [Tips] Please only fill humidifier tank with distilled water.Hard water degrades ALL compatible humidifier filters and yellows them prematurely. Simply wash the filter and the bottom tray every 1-2 weeks. Soaking it in bucket with a mixture of white vinegar and water will clean it right up. The tray can easily be cleaned with dish soap. [Package] 4 Pack HFT600 replacement Filter T filters. Spend less time cleaning, spend more time enjoying life! Colour:White Material:wood pulp paper Size:19.5x16x3cm Package Contents: 4 * filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.