FilterBuy Replacement Humidifier Wick Filters Compatible with Vornado MD1-0001, MD1-0002, MD1-1002. Pack of 6. Pack of 6 FilterBuy Vornado MD1-0001, MD1-0002, MD1-1002 Compatible Humidifier Wick Filters Designed by FilterBuy to fit all Vornado Evaporative humidifiers Including the following Vornado models: 221, 232, 421, 432 and HU1-0021 Premium humidifier wick filter designed by FilterBuy to reduce pollutants. Replace at least once per season. Humidifier FilterBuy: Breathe Better!