I have bought 4 first versions of the mask, received one PRO version and the improvement is amazing! Much easier to breath. First I thought that there is some air gap , but after checking it thoroughly, the increased filter surface are does it. Great job Gill Mask! I love the tightness around the face too. Upgraded all four previous mask to PRO. The only problem I had with the mask, that I wasn't allowed to wear it during my second vaccination here in US. The brainless vaccination organizers insisted that I wear the flimsy cloth of surgical facemask. No arguments that the Gill Mask is much better protection helped. I ended up putting a surgical mask on top of the Gill Mask to calm down the hysteric organizer. You need to educate, run advertisements for the ignorant masses so they won't be scared when someone shows up in your mask. I am not leaving my house without it now. Thanks Gill Mask!