NIJ bulletproof certification encompasses different levels of protection, allowing users to select the appropriate armor based on their specific needs. The NIJ classifies armor into various levels, such as Level II, Level IIIA, Level III, and Level IV, depending on its ability to resist penetration from different types of projectiles. Each level signifies the armor's tested performance against specific ammunition and sets the standard for its ballistic capabilities. Whether law enforcement officers, military personnel, or security professionals, individuals can choose NIJ-certified bulletproof armor that aligns with their required level of protection and threat assessment.