Made of natural fabric with a multi-layer mesh surface to maximize humidifier moisture output and effectively filter limescale. The upgraded material enhances stability and filtration performance for extended use. Compatible with WF813, RCM-832, RCM-832N, PCWF813, PCWF-813, PCCM-832N, PCCM-840, EQ-2119-UL, -830, -832, AC-813, ACR-832, D13-C. Easy installation: Remove the old filter and replace it with this new one. Adjust properly for optimal performance. Replace every 1-3 months under normal use. Use only distilled or cold water in the tank—do not use hot water. Color: White Material: Wood pulp paper Package Contents: 5 x WF813 Humidifier Filters Note: Light reflection and display differences may cause slight variations in color between the image and the actual item. Measurement error allowance is +/- 1-3 cm.