The hardware is actually a stock airsoft gun that's been gutted and stuffed with Xbox 360 controller parts, a rechargeable battery and an Arduino.

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However, tech news site Ars Technica pointed out that Valve has a patent on a controller with swappable parts.

BBC: Game maker Valve Software recruits hardware experts

Shaped like a game controller, it's designed to be used out of the box without extra parts since it comes with many sensors and actuators already on it.

ENGADGET: Arduino Esplora helps you learn microcontrollers without the pesky breadboard