The helmet protects your head, and can mean the difference between instant death and a severe wound, allowing you to seek medical aid where normally you'd be toast. It will not protect your face, or your neck region, and will not protect you against high-energy projectiles, but it provides excellent general protection against small arms and machine gun fire.
Kevlar is a special kind of strong fabric that is designed to stop bullets. Vests have steel plates called "trauma plates" sewn into them in sensitive locations so that the most delicate areas (the heart region, for example) have extra protection. While Kevlar will not protect your from enemy fire completely, you are far better off wearing it than not. High energy projectiles such as sniper rounds may still penetrate Kevlar. The Kevlar vest works automatically.
HE grenades set off a large explosion which kills people within a close radius, and severly damages those just outside the radius. These are particularly effective when used against a group of attackers, as a single grenade can kill a number of opponents.
Flashbangs do little damage to an opponent, even if they are standinfg right on top of them, but anyone looking at them when they go off will be temporarily blinded. The blinding effect diminishes with distance, and is enhanced if the person looking at the grenade is using night vision goggles. be careful using these, as they will blind team mates as effectively as your opposition.
The laser sight paints a small dot on targets even at extreme ranges to help you determine where your shots will fall. Because the laser sight is of less benefit to players with a high latency (high ping), the laser also makes your groups much tighter (in other words, it makes your shots more accurate). The laser sight can be turned off and on by selecting the laser sight item and pressing the use key.
Silencers work by channelling the gases from a fired bullet though a series of baffles to reduce the noise of the explosion. This results in very quiet operation of the weapon, which is vitally important if your goal is to stay hidden from the enemy. In Urban Terror, the silencer also acts as a flash suppressor so if you are in a dark area, your position will not be revealed. The silencer can be removed and attached to your weapon by selecting the item and pressing the use key.
Night vision makes it easier to see other players, especially in dark areas on maps. The main drawback of night vision is that it limits the width of your vision slightly, and increases the blindness effect caused by flash grenades. Once equipped with night vision goggles you can turn them on and off by selecting the night vision item using your next item or previous item keys, and pressing your use item key.
The medkit can be used to increase you ability to heal damaged players. Using the medkit, you can heal players back to 80 percent of their full health, compared to only 40 percent if you don't have the medkit. If you have the medkit item, it will be used automatically when you are attempting to heal other players.
Extra ammo will double the number of clips you start off the round with. So, normally the Beretta gives you 3 clips (one loaded plus two extra). With the extra ammo item you would get five clips (one loaded plus four extras). Extra ammo does not affect the number of knives you start with, or the number of grenades.
