The quality of the bulletproof helmet is usually measured by three indicators, that is, the V50 speed value, the protection area and the weight. Material is not considered, is made of galvanized iron helmet bulletproof helmet is good or bad, usually measured by three indicators, that is, V50 speed value, protection area and weight. Material is not considered, is made of galvanized iron helmet bulletproof helmet is good or bad, usually measured by three indicators, that is, V50 speed value, protection area and weight. Material is not a factor. It's a helmet made of galvanized iron
 
According to the materials of the helmet shell, bulletproof helmets are divided into three categories: metal, non-metal, metal and non-metal composite. In addition to the old helmets, the main materials for making bulletproof helmets are UHMWPE fiber and aromatic polyamides. UHMWPE fiber helmets are lighter, and the bulletproof helmets that meet the level 2 protection requirements of the Ministry of Public Security GA293-2012 "Police bulletproof helmets and masks" weigh only 1.2kg. Infantry bulletproof helmets can prevent shrapnel and direct bullets, and are generally required to resist the impact of 9mm caliber pistol pellets and shrapnel beyond 5m.