The humidifier filter is a replacement for the FZ-A61MFR filter for Sharp purifiers: KC-A40EUW, KC-A50EUW, KC-A60EUW, KC-D40EUW, KC-D50EUW, KC-D60EUW and KC-D40EUB.
The FZ-A61MFR humidifier filter is used to increase the level of humidity in the room where the air purifier works (it acts as an evaporation mat).