This module allows you to add the Rock Smart Mode to vehicles with the Smart-Lok™ Differential Kit sold as an accessory or to change to the Rock Smart Mode on vehicles equipped with a standard Smart-Lok™. The ROCK mode has been specially designed to help cross challenging rocks. When high engine torque is detected at low vehicle speed, Smart-Lok™ will progressively lock the front end and will stay engaged until throttle release to prevent wheel slippage and provide optimal traction. The progressive engagement allows for easier steering when maneuvering the vehicle. Only one Smart Mode Module can be installed at a time. Models with Smart-Lok™ Differential