The most value for money is the 3M 9001A (PM2.5) respirator, its designed to filter very fine particles(PM2.5).
We don’t really need to filter microbial airborne SARS, SWINE FLU particles at this very hazy moment, the main thing to filter is the fine dust particles and the 3M9001A does the job well
It is of course not as efficient as the n95, but its definitely more then sufficient and cost effective
Individually packed in pairs for easy carrying around
Do let others have a chance to buy the masks to ensure everyone has at least a mask for them and their family
Reccomended usage time is 20hours each mask, depending on location and period of use
or
When you feel higher resistance when breathing in