Generally, n95 masks will have a clear N95 logo, and only those produced by regular manufacturers can be used with confidence. If it is not produced by a regular manufacturer, it is difficult to judge whether it is an N95 mask. Even if it is marked with N95, it is uncertain whether it can achieve 95% shielding effect.
Be sure to buy n95 masks made by regular manufacturers and from regular sources. As long as you get it, it should all be real N95 masks. The shielding effect of N95 mask on non-oily bacteria, viruses and other particles can reach more than 95%, so it is a good mask.
Identification method
The way to see if it is N95 mask is to look at the package, see if there is a trade name on the package, whether there is information about the manufacturer or supplier, whether there is a mask certificate or instructions for use, and whether there is a sterilization method for the reused N95 mask.
N95 medical mask is one of nine kinds of anti-particle masks certified by NIOSH. "N" means particles that are not suitable for oiliness, and "95" means that the filtration efficiency reaches 95% under the test conditions specified by NIOSH standard. N95 is not a specific product name. As long as it meets the N95 standard and has passed the NIOSH review, it can be called "N95 mask".