3 ms·
For COVID-19, only N99/FFP3 are effective. People don't grasp the basic math that a N99 mask is NOT just 4% better than a N95 one, it's 5 times better!
by nikolay 2y ago
For COVID-19, only N99/FFP3 are effective. People don't grasp the basic math that a N99 mask is NOT just 4% better than a N95 one, it's 5 times better!