This four - channel system works with the drive - by - wire throttle and the brakes to provide traction control and better operator control during acceleration, braking and cornering. (articles.orlandosentinel.com)
The triple layered channel system each has its own ball, fully enclosed so you don't find yourself falling over them in the dark. (mypetneedsthat.com)
A 7.1 - channel system adds left and right speakers behind you. (techhive.com)