HRUNTING Mark II battle armor

From Halopedia, the Halo wiki

The HRUNTING Mark II battle armor was a powered exoskeleton developed by the Materials Group as part of Project: HRUNTING. It was created during the 24th century as a successor to the Mark I exoskeleton and trialled for use as a force multiplier for special forces and drop troops operating in the colonial frontier. Despite showing promise in these tests, the Mark II proved too expensive and unreliable for these operations, and found little favour in the Colonial Military Authority or interest in the United Nations Space Command. As such, the program was discontinued and by 2400, the remaining suits were only found in military museums or private collections.[1]

The Mark II was later succeeded by the Mark III "Cyclops" exoskeleton.[1]