OPEN BOX NEW- Keep your air purifier running efficiently with the Winix True HEPA Replacement Filter. Designed specifically for the Winix HR900 model, this filter is made with meltblown technology that captures particles as small as 0.3 microns, ensuring that your air is thoroughly cleaned. The pleated design of the filter provides a large surface area for maximum filtration, while the white color complements any air purifier unit. Thanks for shopping our store!