Steering dampers attach to your vehicles steering system and act as shock absorbers for your steering wheel. As you drive down the road and your vehicle hits bumps and pot holes the wheels can shake violently and that motion would normally be transmitted all the way back to the steering wheel where the wheel would try to jerk out of your hands. With steering dampers kickback and vibrations from the wheels are greatly reduced so that you can maintain safe control of your vehicle even in rough conditions.
Heavy duty steering dampers are available for people who frequent rough roads or for those who have upgraded to larger wheels and tires that provide more kickback than normal. If you have gone to bigger rubber, a heavy duty steering damper is a must have addition in order to keep your ride safe and controllable.