Mjolnir/UA, short for up-armor, refers a variety of supplemental armor attachments and accessories compatible with the Mjolnir Powered Assault Armor. Like some other Mjolnir variants, many of the UA pieces are not exclusive to the Mjolnir system, but are in use by regular UNSC Army or Marine troops as well. Many UA attachments are available as Armor Permutations in Halo: Reach.