3 ms·
Really? 3M says to replace if they become too hard to breath through or are soiled. http://multimedia.3m.com/mws/media/447121O/filter-change-out-brochure.pdf h
by hnaccy 7y ago
Really? 3M says to replace if they become too hard to breath through or are soiled.
http://multimedia.3m.com/mws/media/447121O/filter-change-out-brochure.pdf http://multimedia.3m.com/mws/media/447121O/filter-change-out...