3M half mask pre filter

I have a 3m half mask, but as all of us I have limited supply of filters. So I decided to design a pre-filter to prolong their lifespan. And also make the mask look less industrial.

Now this is just pre-filter, the original 3M filter is still doing the hard work. The pre-filter is just helping the filter not to get dirty so fast. Also seals on this type of attachment aren’t perfectly tight, so you always need an original main filter installed!

Before installing pre filter, please check your seal!
Install 603 adaprer, main original filter and dust cover on your mask.
put it on your face,
use your palms to cover holes in Dust filter cover completely.
breathe in.
you shouldnt be able to (dont sufocate yourself)
if there is any leak, it means that you are not protected by original main filter!

This is DYI device, not tested properly, not certified. 3M original parts are always preferable. They did a great job designing the whole filtration system. My design is to be used on