You need a good quality surgical mask plus a mask fitter like the one made by @FixTheMask.
A disposable face mask made out of meltblown polypropylene layer that passes the candle test is likely good.

Why aren't we wearing better masks? Last April, we\u201419 experts\u2015wrote paper on why cloth masks were a good stop-gap measure for COVID. It's just been published in PNAS. Great but... @jeremyhoward and I wrote about our frustration that it's still relevant! https://t.co/tsKHCdQlxr pic.twitter.com/3eoia1B3Ue
— zeynep tufekci (@zeynep) January 13, 2021
2/ Key take away @zeynep @ScottGottliebMD @DrTomFrieden @EricTopol @DrEricDing @ASlavitt: we can all upgrade our masks cheaply. Conditional indoor infection probabilities as low as <0.0001 (0.01%) per hour might be reached with the use of surgical masks and mask fitters alone. pic.twitter.com/bWdWeiZNUS
— David Keating (@DavidLKeating) January 6, 2021
\u201cAllegations of our involvement with the intelligence services are of course false,\u201d says Bellingcat founder @EliotHiggins https://t.co/55V7sJV9or
— UnHerd (@unherd) February 15, 2021
Ivor Cummins BE (Chem) is a former R&D Manager at HP (sourcre: https://t.co/Wbf5scf7gn), turned Content Creator/Podcast Host/YouTube personality. (Call it what you will.)
— Steve (@braidedmanga) November 17, 2020