This is the U-Force. It's a motion-control peripheral released for the Nintendo Entertainment System in the late 1980's. In some ways, it's an amazing piece of technology. In most other ways, it was an absolute disaster.
Unlike Sega's rival Activator peripheral, which we looked at the other day, the U-Force was not a full-body motion-sensing rig. Instead, it was designed to read only the player's hands and arms, translating their gestures into control pad inputs.