n95 masks anti pollution ffp2 ffp3 kn95 mask pm2.5 dust respirator washable reusable masks mask usa warehouse delivery

basic information: name: n95 / kn95 mask white color note: 1. it is recommended to sterilize every 4 hours and then reuse. 2. do not use this product when the environmental pollution is seriously harmful to health or the oxygen concentration is less than 18%. 3. when the product is damaged or breathing resistance increases, please replace it in time. 4. if you feel discomfort such as breathing, dizziness, nausea, etc., you should immediately go to a safe place for inspection and rest.