Vornado filters are specially designed for their humidifiers. The filter must have the correct height, width, thickness and material for maximum performance. Competitors often advertise their filters will work with Vornado humidifiers but these filters don't always fit properly, therefore, the humidifier will not work effectively. Vornado wicks are developed from the highest quality materials that work to absorb the maximum amount of water while filtering the circulating air. Competitor brands are made of different materials not designed for Vornado humidifiers.