Aftermarket Vornado MD1-0002 Humidifier Wick Filter (2 Pack) Fits Vornado humidifier models 221, 232, 421, 432 and HU1-0021-28. 2 filters per box. Measures approximately 7 3/8" x 9 5/8" x 1 3/4". Vornado humidifier wick replacement filters. This is an aftermarket filter.