Kevlar + Helmet

The Kevlar Vest and Helmet, also known as simply Kevlar + Helmet, is a combination of protective equipment found in the Counter-Strike series. The Kevlar Vest can be purchased by itself, while the helmet cannot. 

Overview

               In most games and in Global OffensiveCompetitive, players start the game without armor and helmet. A kevlar body armor costs $650 and reduces damage taken by players from bullets and grenades by a percentage that varies with the armor penetration of each weapon. The kevlar vest protects the chest, stomach and the arms (starting at BETA 1.2) areas of the hitbox while the helmet protects the head.

               The current armor value is always visible as a value and a bar next to the player's health bar on the HUD. In Global Offensive, the icon next to the bar will also change depending on if the player is equipped with a helmet or not.

               Each time the armor is hit, the armor value will drop by a percentage based on how much damage was absorbed. Armor disappears after its value reaches 0. A vest will reduce damage and reduce aimpunch from attacks to the torso by 95%.[1]

               Aside from reducing damage from weapons, Kevlar can also reduce environmental damage such as fire, toxic materials, etc by 50% in some custom maps. Players can also buy a vest with a helmet for $1000, or add a helmet to existing armor for $350 as long as the armor value is still 100, which extends protection to the player's head. The helmet can save players from headshots by most weapons with the notable exceptions of sniper rifles, the Desert Eagle, the SG 553, and the AK-47. Like the vest, the helmet removes aimpunch from headshots, though this time almost completely.

               As long as the armor value is not zero, the exact armor value does not matter and damage will always be reduced. Therefore, having higher armor value does not give better protection unless the value is reduced to zero.