The RGM-79N GM Custom is a variation of the famous RGM series developed by the Earth Federation. It's a production model built after the end of the One Year War. Originally planned as a successor unit to replace the existing mass-production service models, the GM Custom is equipped with a high-output generator and features improved thrusters and auxiliaries. Along with other adjustments such as amplified actuators for faster limb response and additional verniers for better attitude control, the GM Custom possesses vastly superior overall performance and balance when compared to other mass-produced machines.
As a part of the "Augusta series" high-performance MS built after the war, the GM Custom was designed and manufactured using the data and technology, and even spare parts obtained from the development of Gundam-type mobile suits, such as the RX-78NT-1 Gundam "Alex" (where certain design features are evident on the GM Custom). Thus, even among the other high-spec MS of the Augusta series, the GM Custom is still considered as one of the best units of the line.
Despite having output and mobility rivaling that of a Gundam-type MS and being arguably the highest performing GM unit variant during the Delaz Conflict, there is, in fact, nothing that the GM Custom truly excels at, other than being a very balanced general-purpose MS. It can be said that the GM Custom is a "jack of all trades, but master of none".
Due to its construction complexity and high production cost ratios, the GM Custom was not equipped with Beam weapons and its mass-production plans never left the draft stage. As a result, only a limited number of GM Customs were produced and these actual deployment units were assigned only to "ace" class pilots and/or spec-ops teams.
After the events of the Delaz Conflict, the Augusta Base development team, along with their projects, were drafted under the management of the newly established Titans elite unit. Impressed with the GM Custom's performance, the Titans acquired the production line and streamlined the GM Custom's design to be simpler and better suited for mass-production. And thus marks the end of the production life the of GM Custom, and the new RGM-79Q GM Quel is born. This new model would serve as the Titans' mainstay mobile suit until it too was replaced by the RMS-106 Hizack. [Source: wikia]
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