Ballistic helmets refer to headgear specially designed to protect from ballistic rounds and explosive shrapnel and debris. They are, relative to size, the heaviest helmets safety helmets.
Ballistic helmets are made with layers of different anti-ballistic materials placed between the outer hard shell and the inner soft padding. Inner materials may include polyethylene, aramid, UHMWPE, and others.
While few divisions may use different non-ballistic headwear, a standard issue for most United States Armed Forces members will be a ballistic helmet.