Stay Fresh, Stay Protected! 🌟 50 pieces ensure you’re stocked up for the long haul. Designed to fit seamlessly into your daily routine. Experience unparalleled comfort with breathable activated carbon. USA certified lab-tested filters for peace of mind. 5-layer filtration system shields you from PM 2.5 and airborne contaminants. 12x8 cm size USA certified 5-layer filtration This pack of 50 PM 2.5 filters features a 5-layer activated carbon filtration system, designed to provide superior protection against airborne contaminants. Each filter measures 12x8 cm and is USA certified for quality assurance, making it an essential addition to your daily health routine.