?crucial air replacement air humidifier filter - compatible with aircare 1051, essick air part #1051 - models 4dts 300, 4dts 900, h12 300hb, 400hb, 600, 696400hb, 696800, 447400hb - by think crucial (1 pack) is up for auction in Home & Kitchen. This item is in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.