The bulletproof performance of explosion-proof vest is mainly reflected in the following three aspects: (1) at present, many soft bulletproof vests can protect against pistol bullets, but to prevent rifle bullets or higher-energy bullets, ceramic or steel reinforcements are needed. (2) the high-speed fragments produced by the explosion of bulletproof fragments such as bombs, mines, shells, grenades and other bulletproof fragments are one of the main threats on the battlefield. According to the survey, the order of threats faced by soldiers on the battlefield are shrapnel, bullets, explosive shock waves and heat. Therefore, the function of bulletproof must be emphasized. (3) to prevent the non-penetrating injury bullet from hitting the target, it will have a great impact, and the injury to the human body is often fatal. This kind of injury is not penetrating, but internal injury, which is life-threatening in serious cases. Therefore, the prevention of non-penetrating damage is also an important aspect of bulletproof performance of bulletproof vest.
 
Up to now, there have been three generations of modern bulletproof vest: the first generation is rigid bulletproof vest, which mainly uses special steel, aluminum alloy and other metals as bulletproof materials. The characteristics of this bulletproof vest are: heavy clothing, generally about 20 kilograms, uncomfortable to wear, great restrictions on human activities, with a certain bulletproof performance, but easy to produce secondary fragments.
The second generation bulletproof vest is a soft bulletproof vest, which is usually made of high-performance fabrics such as multi-layer kevlar. It is light in weight, generally only 2 to 3 kilograms, and has a soft texture, good fitness, comfortable to wear, and good concealment when wearing it, so it is especially suitable for the daily wear of police, security guards or political dignitaries. As far as bulletproof capability is concerned, bullets fired by pistols 5 meters away can generally be prevented from producing secondary shrapnel, but they are deformed greatly after being hit by bullets, which will cause some non-penetrating damage. In addition, bullets fired by rifles or machine guns are irresistible with soft bulletproof vests of general thickness.
 
The third generation bulletproof vest is a kind of composite bulletproof vest. Generally, lightweight ceramic sheets as the outer layer and Kevlar and other high-performance fiber fabrics as the inner layer are the main development direction of bulletproof vests.
By the way, the four-stage metal bulletproof vest developed and designed by Gatekeeper Technology Group adopts special alloy high-chip lap joint, which has excellent bulletproof performance, wears freely and does not affect the exertion of various technical and tactical movements. Type 79 7.62mm light submachine gun and 51 type 7.62mm pistol cartridge (lead core bullet) are used for room temperature, high and low temperature and immersion resistance tests, and the bulletproof layer meets the requirements.