Armored Powered EXoskeleton was a power armor designed as a competitor for the CASPer, sacrificing armor and firepower for mobility and compactness. The aliens who designed the armor didn't take into account the size of typical human troopers, and the more compact armor could accommodate operators nor more than 175 centimeters tall.
APEX armor has no onboard weapons and possesses limited jump capability. The armor can repel small arms fire but is vulnerable to heavier weapons. Unlike CASPers, soldiers wearing APEX armor can fit in standard vehicles as the suits only stand 185 centimeters tall.
Bjorn's Berserkers utilize APEX armor in reconnaissance roles.