You’ll see things like IIIA and IV across our site.These signify the stopping power of the armor. Below is a very simplified list and explanation.

IIIA = Stops select pistol bullets – Example: 9mm & .45
III = Stops select rifle bullets – Example: 5.56 & 7.62
IV = Stops select AP (Armor-Piercing) bullets – Example: .308 & 7.62 API