I just picked one of these up today. It was a bit of a chore to get everything properly set up and dialled but now that I've got it working the way I'd like, I think it's a really cool little aid to immersion. It's basically an amplifier that attaches to the post on your gaming chair and delivers feedback based on audio cues from your games. I fired up War Thunder and took a spin in both a tank and a plane and was giggling like a simpleton the entire time. I could feel the vibrations and the thump as I raised and lowered the landing gear and flaps on my plane and the low rumble of the tank engine, briefly punctuated by the kicking thump as I fired the cannon was quite intense.
You can adjust the sensitivity and intensity on the fly. I think if you play flying or driving sims, it's a great little addition to a force feedback controller and a Track IR in making the game even more immersive.
http://www.thebuttkicker.com/gamer2 (http://www.thebuttkicker.com/gamer2)