The unique shape of the Hazel Custom is faithfully recreated. This includes:

• Exterior armor
• Auxiliary actuator units
• Movable booster pods
• Backpack
• Leg reinforcements

Following heavy damage sustained by Lt. Wes Murphy's Gundam TR-1 [Hazel] in combat with Zeon remnants, it was repaired and enhanced using parts from an RGM-79Q GM Quel and spare Hazel components. This upgraded version, called the "Hazel Custom," leverages combat data and developmental insights from the original Hazel, resulting in a more balanced and complete mobile suit.

• Enhanced Integration: Improved balance and a unified external appearance due to better integration of enhancement parts with the internal structure.
• Performance Boost: Lighter weight and increased thruster output provide about 10% greater acceleration.
• Experimental Cockpit: Features a 360-degree panoramic monitor and linear seat system, along with an upgraded operating system.
• Model Number Update: Changed from RX-121 to RX-121-1.
• Shield Replacement: Uses a standard shield temporarily, as the unique shield boosters were lost in previous battles, slightly reducing mobility.
• Armor Color: Remains mostly grey due to time constraints preventing a repaint in Titans colors.

• Comparable Specs: Basic specifications similar to those of the GM Quel, including generator and thruster performance.
• Leg Sections: Equipped with thermonuclear rocket engines with an output of 17,500 kg each.
• Backpack: Contains a movable booster pod and a thermonuclear reactor that serves as both a supplemental generator and hybrid jet/rocket engine, with outputs of 390 kW and 18,000 kg.
• Support Actuator Units: Retained from the original Hazel, compatible with the same equipment and enhancement parts.
• Weapon Latches: Located on the center skirt armor and above the cockpit hatch, allowing for flexible weapon options.

• High Mobility Form: Matches the original Hazel.
• Assault Form: Uses the booster pod from the RMS-117 Galbaldy β High Mobility Type, two shield boosters, and the extendable shield from the Galbaldy β.

The Hazel Custom showcases significant performance improvements and advanced capabilities, making it a highly effective mobile suit in combat.