The RGM-79L GM Light Armor is a variant of the RGM-79 GM that first appears in the Mobile Suit Variation series.
The GM Light Armor was made alongside the RGM-79SC GM Sniper Custom to meet the demands of some ace pilots who wanted improvements to their RGM-79 GM. Based on the premise of beam weaponry being the decisive factor in battles as a single beam shot can critically damage a mobile suit, the GM Light Armor undergoes comprehensive armor reduction (thinner armor and loss of shoulder and ankle armor) in exchange for higher mobility to enable it be a speedy unit for hit-and-run attacks. As a result, this machine was favored by many of the Federation Forces' ex-Fighter pilots.
Federation ace pilot Gary Rogers piloted the GM Light Armor during the One Year War, using the mobile suit's superior mobility in hit-and-run attacks.