The RX-121-3C Gundam TR-1 [Hyzenthlay] is a machine plan in which the know how obtained from the RX-124 Gundam TR-6 Woundwort High-Speed Fighter Form is fed back to the RX-121-2A Gundam TR-1 (Advanced Hazel). As a result, virtually all the RGM-79Q GM Quel parts that remained in the Hazel are replaced by newly constructed enhancement parts. Because it uses the unmodified upper body of the Woundwort high-speed fighter form, its head, chest, and shoulders are very different in shape from those of the Hazel. This substitution is possible because the upper body of the TR-6 is the same size as the Hazel's Primrose escape system. It appears that the TR-6 components are actually installed on top of a RX-121-2 Gundam TR-1 Hazel Owsla torso, since the head and chest structures of the Owsla are visible underneath the new enhancement parts. The TR-6 booster pod is likewise connected to the same movable booster pod used by the original Hazel. Finally, the chest and arms of the base TR-6 mobile suit are attached to the waist of the Hyzenthlay as a sub arm unit.