The RX-178 Gundam Mk-II are three prototype mobile suits developed by the Titans, an elite special unit of the Earth Federation forces, in UC 0087 - the first Gundam units seen in "Mobile Suit Zeta Gundam". Aside from a new paint job of dark blue and black with red and yellow highlights, the Gundam Mk. II bears great aesthetic similarities to its One Year War-era predecessor, the original RX-78-2 Gundam from "Mobile Suit Gundam". The Mk. II represented a small increase in mobility compared to the original, and with the deletion of the cumbersome and expensive core block system, room was freed upon for a more modern panoramic cockpit setup (a more or less standard accoutrement for mobile suits in the same series and time period), which is designed to offer increased situational awareness to the pilot. Armaments are fairly standard Gundam fare, including a beam rifle (chronologically speaking, the Mk. II's beam rifle was the first of such weapons to be powered by a replaceable e-pac device; this was later retconned with "") and twin beam sabers. Vulcan guns are not installed in the Mk. II by default, unlike previous models; however, an optional set can be added as an ejectable pod. The Mk. II may also arm a "clay bazooka" weapon, which is capable of disabling a mobile suit's mobility via an adhesive warhead (though it can equip normal explosive shells if desired). Aside from the aforementioned mundane enhancements, the Mk. II's most substantial contribution to mobile suit technology and largest upgrade over its predecessor is the then-revolutionary movable frame construction, which later inspired the designs in the novel Gundam Sentinel. Paradoxically, the Gundam Mk. II is "not" armored with the wonderfully durable Gundarium alloy material, first introduced in the series on the original RX-78 Gundam, making it no more or less physically durable than mass-production mobile suits of the era (the term Gundarium is a creation of the Zeta Gundam series; formerly, the same material was known as "Lunar Titanium" in "Mobile Suit Gundam", and was renamed (or retconned from a meta standpoint) in honor of the original Gundam).