This is a skin for the Riot Helmet item. You will be able to apply this skin when you craft the item in game.
A mid-tier helmet that protects the user's head. Made without the need for High-Quality-Metal, the helmet is an inexpensive form of protection that offers exceptional melee resistance and amicable projectile resistance. It comes in a rather form-fitting default black skin, which tends to camouflage rather well, with several other user skins in the same vein.