Armor vest and helmet

The Armor Vest and Helmet or Security vest, is a protective vest and helmet worn by the Security guards in Black Mesa.

Overview
The Security vest is worn by all Security Guards in Black Mesa, the armor vest is capable or absorbing (and possibly even deflecting) low-caliber rounds, it also protect users from explosives and other type damages what would be usually fatally without one.

The Helmet, like the Security vest, it also worn by all security guard in Black Mesa, The Helmet protect security guard from damage to the head, but only low-caliber rounds like MP5 and shotgun pellets, and their face are uncovered which is still vulnerable to bullets. The Helmet cannot protect the users damage from high-caliber round like .357 Magnum, Desert Eagle and Crossbow, which cause these bullets penetrate trough the Helmet, killing the guard.

The security vest and Helmet as well Glock 17 or Desert Eagle is very important equipment for all security guard, intrude Barney Calhoun. Otherwise the guard have no access to "hazard zone".

Unlike the HEV Suit and Powered Combat Vest, the battery cannot be used for increasing the armor point. Instead, picking up a fresh vest is required to increase the armor point. In Half-Life: Blue Shift, picking up the Helmet will gain 40 Armor point. Picking up Armor Vest will gain 60 Armor point.

Behind the scenes

 * The Security Guard's Helmet in alpha version of Half-Life have MP (Military Police) on it helmet.
 * The Opposing Force "Otis" security guards were originally to wear helmets, like the "Barney" version. While removed in the main game, it is still present in the multiplayer model.
 * In Half-Life 2 Beta, a model of Helmet can be found, suggest that Barney Calhoun was to wear this Helmet.

Trivia

 * The Helmet in GoldSrc version of Half-Life will protect the guard from taking bullets and Crowbar damage. However, in Source version, the helmet won't protect the guard, and a headshot can kill the guard instantly (as provided the guard is not attacking the player when attempting to kill the guard with headshot, otherwise the guard can survive a first shot).
 * Though the helmet will protect the guard from taking damage from low caliber round. However, if the player use cheats and shoot the guard's helmet for long enough time, it possible to kill the guard. Every 50 bullet of 9mm and 10 shotgun shell shot will cause the guard lose 1 health point.