it works mostly [SEP] i had to bump this from to stars after working a hr shift they left something to be desired they mostly work but there were a few issues with fogging still better with than without original review i am practically blind without my glasses and foggy lenses from having to wear a mask is almost as bad as not wearing my glassesi was not very hopeful for these mask inserts but to my surprise they actually seem to work as long as i do not go jogging in them i did a test by blowing into the mask and it took some effort to get my glasses to build up a good fog the real test will come tomorrow when i wear it to workthe only down side so far is a rubberized smell i am hoping will disapaite with a good airing our