Filters-NOW UFCBW9 Humidifier Wick Filter Bionaire 900 Fits Bionaire models C22, C33, W2, W2S, W6, W6S, W7, W9, W9H, W9S, W25, W0210, W0210S, W0305, W0310, W0340, W3040, WC0840, and WC2845. 2 filters per box! Measures approximately 7 3/8" x 8 3/4" x 2 3/4". Bionaire humidifier wick filters. This is an aftermarket filter.