That’s right four hundred forty masks (6 cents per). Yes it’s Amazon but this is a good deal.
This is the link: https://www.amazon.com/dp/B08J1THV9G
It is from a sub-company of Amazon that specializes in deals so it is legit-ish. The ones a close friend received came in an official 3M branded box (a huge brown box not retail packaging).
They’re individually packaged in the official sealed wrappers, had lot codes on them and looked to be in good shape. No weird smells either and the elastic and nose pieces seemed fine. No expiration dates unfortunately if that’s super important but the box had a barcode and I suppose you could contact 3M and ask about that lot number.
In my experience with this (type) of mask the elastic does fail first after a few reuses. But I can’t say definitively that the mask itself wasn’t compromised before that as I have no way to scientifically test it. Sometimes I get discoloration on the inside too maybe from my skincare products or something which probably doesn’t impact function but does make them a little gross seeming to rewear after that.
If you replaced the elastic on these you could maintain a good seal through many re-uses but I understand the filtering doesn’t last forever. I’ve seen people on reddit say I think 40 total hours absolute max wear-time and that’s assuming multiple rest periods in a paper bag for several days or a week between like 4-5 wears I think of maybe 8 hours max each. I am pretty sure that liquids compromise the filtering. So if you enter an area with misters/mist or very high humidity or get water all over them that compromises the filtering I believe and is cause to discard.