12 PCS PM2.5 Activated Carbon Face Mask Filter ... - amazon.in
Mar 17, 2020·Size of Adults Mask Filter: 4.7''x3.1''. Suit for adults mouth mask insided with fliter slot. How to use:Insert the PM2.5 filter along the inside of the mask and use it, Refer to Fifth picture. Disposable supplies can't be reused or washed. Recommend replace filter once a week for the best effect or 3 day If there is serious contamination.