Max defense - max defense replacement filters are white in color and allow air to pass more freely hence making breathing easier while these filters are installed. these are designed to filter out 80% of pm2.5 pollution and germs that exist around us and can block 94% pollen dust dander and mold. • compatibility - compatible with slotted clenare nasal filter body. only for use with clenare nasal filter body. • certified & tested - clenare replacement filters have been tested by international laboratories like nelson labs usa for filter efficacy. • usage - replacement filters are designed to fit inside the nasal filter body. • breathable - minimum resistance to air flow & cleaner air to breathe. the filters come with high permeability media which has minimum resistance to air flow and makes it super easy and comfortable for you to breathe through. • protection upto 50 days - this filter pack can give protection upto 50 days. replace when filter turns black. replace every week for best results. the replacement filters are easy to replace. • package contents - clenare replacement filters (slotted) - max defense (pack of 5) • note - choose the size which matches with your filter body. each pack comes with 5 pairs of filters.