It prevents paintballs from smashing into your face
"No Fog" lens fogs...
This is the first mask I ever bought. I didn't have a lot of money, I was walking through walmart and figured for $20 bucks, why not try it out?
The first few games with it were nice and quick, so I didn't have any fog issues. I did have a problem with the padding around the nose, it was kind of tight and pinched my nostrils closed. I just picked at the foam until it didn't do that anymore. The next weekend we ran longer games, and it got to the point where I couldn't see a thing. I was ready to throw it away when my friend gave me a thermal lens he had from one of his other masks. I switched the lens, which did take me a few minutes longer then I was anticipating, but I got way more use out of it then I ever expected.
It's quite possible that it would be more cost efficient to spend a little more for a higher end mask, but I gotta say, replacing the lens made all the difference. The mask sits nice and secure, it can take a beating, I've had the same one for almost 8 years, I like the way this mask fits me because I can look back behind me without bumping it against my shoulder and I like the simplicity in the style.
It's not perfect, but this mask has proven itself to me. I'd even go back to Walmart just to buy another if something were to happen to mine. It's inexpensive and will last many years. That alone makes it a good product in my opinion.