A Marine wearing M4X Armor.

M4X Armor is an advanced body armor system used by the United States Colonial Marine Corps. It is an upgrade of the M3 Pattern Personal Armor.[1]


M4X Armor[]

An update to the aging M3 vest, M4X armor provides better protection against high-velocity impacts than its predecessor without sacrificing mobility. Instead of a basic vest and infantry 'bucket' helmet, the M4X incorporates full-body protection with armored sleeves, thick gloves, and a full-face helmet complete with a light ballistics-resistant visor.

The armor is also augmented with a lightweight body frame to help the wearer maintain his balance whenever he is hit with tremendous force, like body blows from an onrushing Xenomorph or Yautja. Most notably, and unlike its predecessor, the armor also incorporates light resistance to Xenomorph acid blood.

While the M4X is superior in all aspects to the M3, the armor is still undergoing field testing with several Marine combat units before being issued to the entire US Colonial Marine Corps.

Acid Resistant Body Armor[]

Based entirely on the M4X's body armor frame, the prototype, researched and developed by Dr. Mark Cruz, utilized an acid resistant polymer coating, which was an upgrade to the limited acid resistance of the old M3 vest. The acid resistant armor provided full body acid resistant protection with sleeves, gloves, and a full face helmet.



  1. Aliens versus Predator: Extinction, Infantry unit description