The dumbest thing in the world and it works great. Essentially, this helps keep the motor in line with the frame when the swingarm bushings are flexing and when they aren't. Keeps the rear of the bike stable in all turns and does not wobble. To be honest you can replace swingarm bushings with bearings and rubber isolators with new ones every few years and the chances of the back wobbling are pretty slim, but it's definitely the right answer to eliminate that wobbling.