Armor Vest is protective gear, that adds additional defense to Lo Wang's health bar when picked. Vest comes in two variations: normal grey, that gives +50 armor and kevlar red, which gives +100 armor. Lo Wang can have maximum 100 armor at the time. The vests are usually hidden all over the level but only in few at the time.
Armor Vest returns in Shadow Warrior (2013), now simply called armor and has new visual design. As Classic one, the new one appears in two variations: smaller chest plate gives +35 armor, while bigger one gives +75 armor. As in Classic, armor is pretty rare in the levels. The maximum armor Lo Wang can have at a time has been reduced in the reboot from 100 to 75.
Armor is useful when fighting large groups of enemies or bosses.