NIJ3A is equivalent to China's police ballistic protection standard GA2 level. GA's test requirements are higher than NIJ, and the initial speed of the bullet is faster.

1, first of all, the level of ballistic protection, there are many foreign standards, but commonly used is the U.S. NIJ standard, there are six levels of this standard, respectively: Ⅰ, ⅡA, Ⅱ, ⅢA, Ⅲ, Ⅳ. Protection ability from low to high, where the ⅢA level requires the ability to prevent the 9mm pistol shot fired by micro-charge, the speed of the bullet: 420m / s; ⅢA level under each level is to prevent 9mm pistol, the speed of the bullet: 360m / s or less.

2, most of the general foreign customers require bulletproof vest protection level is ⅢA level, Ⅲ level of protection is in the front and rear of the vest plus two 300mm * 250mm ceramic composite plate, no plate thickness: 18mm, weight: 2.6kg, this level requires the ability to prevent NATO M80 ammunition (7.62 * 51 ammunition, bullet speed: 800m / s) in this level and AK-47, 56 type Rifles fired by ordinary ammunition. Level Ⅳ also need to add ceramic plate, plate thickness: 21mm, weight: 3.3kg, required to be able to prevent M1 launched armor-piercing ammunition, bullet speed: 850m / s.

3, GA141-2001 "General technical conditions of police body armor" in the police body armor bulletproof grade settings

Bulletproof grade Firearm type Bullet type Bullet muzzle velocity (m/s) 

1 1977 type 7.62mm pistol 1964 type 7.62mm pistol ammunition 300-320 

2 1954 type 7.62mm pistol 1951 type 7.62mm pistol cartridge 420-450 

3 Model 1979 7.62mm Light Assault Rifle Model 1951 7.62mm Pistol Cartridge 480-515 

4 1954 Type 7.62mm Pistol 1951B 7.62mm Pistol Cartridge 420-450 

5 1979 Type 7.62mm Light Submachine Gun 1951B 7.62mm Pistol Cartridge 480-515 

6 1956 type semi-automatic rifle 1956 type 7.62mm ordinary ammunition 710-735 

Note: Bulletproof grade 6 or above is listed as special grade

4, bulletproof vest grade ⅢA or below is soft and does not require ceramic plates. There are domestic and imported materials for the bulletproof layer of soft body armor. The domestic material is white ultra-high strength polyethylene fiber; the imported material is Kevlar (KEVLAR) yellow; the price of body armor is related to the material used, but also to the area of protection, the larger the area, the higher the price. Common bulletproof vest has three types of protective area: undershirt type (0.27 square meters) vest type (0.32) full protection type (with crotch guard 0.60).