The aFe POWER BRAKELOGIC Exhaust Brake Control Module is a simple plug and play module that electronically closes off turbocharger vanes to provide engine braking. It also controls the transmission to downshift to enhance braking. This BRAKELOGIC module creates up to 130 retarding horsepower and up to 70psi of exhaust back pressure. The factory tow haul switch will allow you to turn on the unit and simply pressing on the brake will engage it. The aFe POWER BRAKELOGIC module will help maintain and control your speed during steep descents. It is perfect to use while a trailer is connected or heavy load is carried. The engine braking created will eliminate overuse of the brakes and prevent them from overheating. Recommended for vehicles with automatic transmissions.