Just an FYI based on personal experience. Try the reflector based TrackClip that came with your TrackIR, before you spend $40 on the TrackClip Pro with the IR LEDs. The only reason you should need the Pro is if your PC setup is in a room that is brightly lit (sunlight). The TrackClip that comes with the TrackIR actually works better than the Pro, especially if you are in a darker room, like a basement, etc, since the TrackIR unit is providing IR illumination from the unit for the TrackClip. Just thought I'd share, since I built a homemade IR LED array and had mixed results. After watching a few youtube videos, I grabbed my TrackClip and mounted it to my headset, and WOW, functions great! Anyways, hope I can save someone from spending $$$ or time unnecessarily.