This anti-fog is, in fact, legit anti-fog. I wear a ghost balaclava and it fogged my $80 Revision glasses up like a mother. I now can skirmish all I want and not have to stop every ten feet and de-fog.
It works really, really well
Lasts basically until you wipe the film it leaves off your glasses
Includes a little bag that you can keep towelettes in
Seems like a towelette could last you indefinitely unless you lose it
I'm now the coolest guy around because I de-fog all my team-mates
Expensive, but all in all worth every penny
Rating: [5 of 5 Stars!]