This armor, normally of hard or semi rigid construction, protects against 7.62mm full-metal jacketed bullets (US military designation M80), with nominal masses of 9.7 g (150 gr.), impacting at a velocity of 838 m/s (2,750 ft/s) or less. It also provides protection against threats such as 223 Remington (5.56mm FMJ), 30 Carbine FMJ, and 12-gauge rifled slug, as well as the level I through III–A threats. Level III body armor is clearly intended only for tactical situations when the threat warrants such protection, such as barricade confrontations involving sporting rifles.

This armor protects against .30–06 caliber armor-piercing bullets (US military designation APM2), with nominal masses of 10.8 g (166 gr.) impacting at a velocity of 868 m/s (2,850 ft/s) or less.

Level IV body armor provides the highest level of protection currently available. Because this armor is intended to resist “armor piercing” bullets, it often uses ceramic materials. As with Level III armor, Level IV armor is clearly intended only for tactical situations when the threat warrants such protection.