This humidifier filter (evaporator pads) is coated with a non-soluble wetting agent to increase humidifier efficiency and fits GeneralAire power humidifier (drain type) models 1099 series. It also features aluminum evaporator material which is enclosed in heavy wire frame and channeling and has a super absorbent coating for maximum water distribution and increased humidity output. Excess coating may shake off before first use. It measures approximately 12 x 14-1/4 x 1-1/2. For optimum performance, replace filter twice a season.