Amazon.com: Razer Hydra PC Gaming Motion Sensing Controllers (RZ06-00630100-R3U1) : Video Games
Razer - Beat Portal 2 with your Razer Hydra and looking for your next fix? Look no further as we are providing fully integrated motion gaming support for Valve's titles, both present
Razer Hydra Tutorial - YouTube
Valve, Razer and Sixense: Motion-Sensing on Steam – Techgage