The Powertrax Grip PRO is a gear driven limited slip differential designed to be among the strongest and most durable in the industry. It combines the smooth operation of a limited-slip differential, with the strength of a fully-machined, forged steel case. Using 3x2 spiral gear technology, the Powertrax Grip Pro delivers progressive and variable traction. Based off of throttle input, you are in control of how much traction is applied, which is great for situations where finesse is as important as extreme traction. On the road, in rain and snow, and on the track, Grip Pro is a winner!