A mask fit test is a way to know how well a mask works for the person wearing it. You don't need to do a fit test to benefit from wearing an N95-style mask.
Step 1
In order to get a good mask fit your face needs to be clean, razor-shaven (if you have facial hair). If you cannot razor shave your facial hair, a large elastic elastic rubber band may be used to achieve a good fit.
Step 2
Technical details
If interested, please see the technical details on this method of fit testing.