can be used for up to 28days.
2.continuously kills bacteria including：MRSA，TB，MS-2，influenza so on….
3.continuously inactivates viruses including: SAES,influenza A, adenovirus and Human Rhinovirus（common cold）
4.inactivates bird flu*
5.Exceeds 99% filtration efficiency against bacteria and virus
Note: This product only contains one n99 mask, which is packed in mail-order box packaging. If 24 masks are purchased at one time, they will be delivered in the original box.