Made of natural fabric, multi-layer mesh to maximize the output of humidifier moisture, but also better filter Limescale, the upgraded material makes the filter more stable and filtering, can be used for a longer time. Including for WF813 RCM-832 RCM-832N,for PCWF813 PCWF-813 PCCM-832N PCCM- 840,for EQ-2119-UL -830, -832, AC-813, ACR-832, D13-C, -832, etc. Easy Installation,Remove the old filter in your humidifier, put this humidifiers filters in its place and adjust it well. Normal use 1-3 months need to be replaced with distilled water or cold water to fill the tank, not hot water. Colour:White Material:wood pulp paper Package Contents: 25 x WF813 Humidifier 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.