Blueair pre-filter in saffron red color for the blue pure 411+ air purifier. form meets function in blue pure 411+'s colorful pre-filters. The stretchy fabric allows you to customize the color to match your style, as well as extend the life of the primary filter, catching large airborne particles such as dust, lint, pollen, and pet hair. Removable, washable, and reusable the pre-filter is designed to be used again and again. Hang to dry.