A very, very high-quality and sturdy lightweight version of its realistic counterpart.
As the picture clearly shows there is a speckled layer of paint. This improves grip for a possible helmet cover, which is very recommended. Airsoft-club has a large selection of these helmet covers in all of the camos it offers.
Even though it's made out of some sort of plastic that allows for a slight bending, it is still heavy. Heavy enough to consider not wearing it to any of your skirmishes ;). A good example of military roleplay taking its toll, hehe.
The inside of the helmet allows for complete customization and the pads make for a very comfortable experience. The chin strap can be completely fiddled with too.
The real U.S. deal. Buy it.