SWAT Helmet

Cosmetic only. The head slot it takes up gives nothing back, which is a small joke on its own considering the real article is built to stop bullets.

Tactical Skeletons carry it, so you are looking at the Dungeon after Plantera is down. By that point you are already sweeping those halls for far better loot, so treat this as something that turns up on the way rather than a farm target of its own. If you are after the whole modern soldier look, the other tactical drops from the same wing finish the outfit.