The designation 3a A3 III A armor are often used for a body armor or class 3 ballistic plate plate carrier. The soft NIJ 3A bulletproof vest is most commonly purchased as protection against knives and bullets from handguns, while the class 3 ballistic plate is used as protection against rifle bullets. The class 3 ballistic plate is somewhat outdated and is usually replaced by a 3+ or class 4 bulletproof plate.