The gel layer regulates temperature and can reactively change its density in a few seconds. Underneath that layer is a gel-filled layer. Underneath the alloy shell is a thick black armored titanium nanocomposite bodysuit. The armor's outer shell is composed of a multilayer alloy of remarkable strength which has been augmented with a refractive coating capable of dispersing a limited amount of Covenant energy weapon impact. It is hardened against electromagnetic pulse and radiation, and has filters that are completely effective at removing toxins and bacteria from local atmosphere. MJOLNIR is a sealed system capable of extra-vehicular activity or operations in toxic atmosphere and vacuum.

Planning and research for the revised MJOLNIR battlesuit began in 2511 alongside the SPARTAN-II project over the course of 14 years, its development gave birth to many new technologies that would later see major adoption throughout the military.

Catherine Halsey, the MJOLNIR armor represented her vision of creating a slim powered exoskeleton capable of taking full advantage of the physical capabilities of a SPARTAN-II. Developed parallel to the SPARTAN-II program by the Office of Naval Intelligence's Materials Group, the MJOLNIR powered assault armor was a radical redesign from previous large, bulky exoskeletons, streamlining their design into a compact suit of armor practical for use in the field.

Fallout 4 spartan armor