hi, i'm looking for a proper, reusable respirator mask since im back in school and also have to go to the doctor soon ish and we ran out of properly isolated masks

as said, has to be reusable, idk jow any of this works, i think one switches filters? are these standardized?

also part also also part of the reason is that i so far did not actually understand how covid actually spreads until i just read an article that properly explained it. i've said some pretty stupid shit quire a bunch of times when talking to people about this...