This kit uses the variable vane turbocharger. The variable vane design used in diesels today can reduce turbo lag, emissions and increase power and it can also be used to slow you down. BD utilizes this technology by electronically closing off the turbine vanes which can create up to 130 retarding horsepower. This braking force will help to maintain your speeds on descents and curves, giving you better control of your truck and load. The Variable Vane Exhaust Brake rotary switch offers three different modes including: Stock, Vane Control Only and Vane Control with Aggressive Downshift. Easily and simple installs by plugging into existing factory ports any by mounting the rotary switch on your dash.