The approximate size of this filter is 11.5 x 10 x 1.75. This item must be replaced at least once per year for optimal performance. This item is sometimes called a water panel, media filter, evaporator pad, or humidifier pad. This component is also known as HUM-1725052 and fits the HUM-SFTBP series humidifiers. The filter includes the wick that goes into the water distribution tray.