Track IR Explained

I thought these videos pretty much say it all,

https://www.youtube.com/watch?v=_AO0F5sLdVM

https://www.youtube.com/watch?v=mThzbI60uJU - watch the first part of this one to see what exactly comes in the box.

http://www.naturalpoint.com/trackir/02-products/product-videos.html

If you use a headset here's what you want to get - Track IR 4 Pro Bundle w/Track Clip Pro.
http://www.naturalpoint.com/trackir/promo/promo_landing.html?promoname=trackclipprobundle

If you don't wear a headset, then this comes with everything, uses a clip for a hat to mount the LED reflectors - can always order the Track Clip Pro later if you get a headset and you want to snap it on the headset and not wear the hat.
http://www.naturalpoint.com/trackir/02-products/product-TrackIR-4-PRO.html

Remember, you can tweak the response curves for all 6 axis to make them more/less sensitive - it's extremely customizable and very easy to adjust the response curves. You'll probably start out with less sensitivity, so it might seem like you're moving your head more than you want to get the view you want, but over a week or two you'll get the hang of it and start increasing the sensitivity of various axis. Eventually you'll have it set so you only move your head a few degrees and it results in all the movement you need on screen. It's great.

Oh good grief I am going to have to try to put this thing in the budget! Thanks for the link!