Continuing the SEED theme, this is Yzak Joule's machine. It's also a plundered machine...
Duel apparently means "fight" or "confrontation." It's designed for close combat.
It's Master Grade. I photographed the unassembled, unpainted model with the assault shroud removed. I removed it so it's easier to achieve the MG-specific poses. The shroud is apparently "clothing that wraps around the dead," not armor or armor.
Isn't the shield supposed to be worn on the back? So I forced it to fit between the backpack and waist for the photo.
It would probably look better if I painted it and applied decals and stickers, but it looks like it'll be stored as is. (Time...)

MG GAT-X102 DUEL GUNDAM (without Assault Shroud) | TAZYA's Gunpla works