Ballistic Values are the proper interpretation of all testing standards, materials , and equipment used to defend against incoming rounds. The truth is most materials used by this industry are pretty standard , Arimad, Polyethylene, Glass, Lexand, Ceramics, Hardened Steel, and Fiberglass. With the number of layers and thickness playing the primary roll in managing the threat . All of these materials have their strengths and weaknesses. For instance the fabrics ( Arimad and Polyethylene ) are light weight and are easily formed into useful shapes at low cost, the drawbacks are the relatively short lifespan and the initial cost of the fabric. The fabrics do the best job stopping (Ball) ammo both rifle and pistol by weight , but fall short when it comes to the steel core rounds. It`s just the opposite with the U.L.Rated ( Architectural ) type materials like glass and steel. While these materials have no real expiration date they still require some degree on maintenance to keep them in good and serviceable condition and the weights range from heavy to extremely heavy. That`s why you regularly see a combination of these materials used to achieve the the desired effect.

The two primary institutions tasked with setting standards for testing these materials are the N.I.J ( National Institute of Justice) and the U.L (Underwriters Laboratory) . With the NIJ Testing consisting mainly of fabric and ceramic composites held or worn by officers , and the U.L testing architectural building material . Where the whole thing seems to go off the rails for most is when they confuse the testing standards from one with the other. For instance, a NIJ Level 3 Standard designates a composite capable of stopping rifle rounds and a U.L Level 3 Standard designates a material capable of stopping a pistol round. Big Difference. Another big one is NIJ Level 3a (Pistol) compared to NIJ Level 3 (Rifle) " the 3a will not stop a rifle bullet" at all . In fact it takes almost (4) 3a`s to do the job.

The following is a simple explanation of the standards. Hope this helps. Do your research and know what your fielding and why.

NIJ Level 3a (Pistol) : Stops .44 Mag to 1450 fps. ( 9mm, .45, .40, .357, .and most Shotgun Rounds )

NIJ Level 3 (Rifle) : Stops .308 (Ball) ammo to 2800 fps.  ( 5.56, .223, 7.62x39 )

NIJ Level 3+ ( Rifle) : Stops 7.62x39 (Mild Steel Core)

NIJ Level 3++ (Rifle) : Stops 5.56 (M855) Steel Core " Green Tips".

NIJ Level 4 (Rifle) : Stops 30.06 (AP) Rounds

U.L Level 5 Glass (Rifle) : Stops .308 (Ball) ammo

U.L Level 3 Polycarbonite (Pistol): Stops .44 Mag and below