Blast Cabinet Visibility

There's a guy on GarageJournal who is selling blast cabinet protector screens. I'm intrigued but he's not really been too forthcoming with more info. I was able to get him to forward a pic but I'm still up in the air on giving one a try. They're $30. This is looking through it ...

View attachment lens protector.jpg

Anybody else given one of these a try? I don't even know the manufacturer's name yet.