The APR Power Control Unit (PCU) is an inline tuning device designed to increase the horsepower and torque of the vehicle! The plug-and-play control unit piggybacks off the primary Engine Control Unit (ECU) to increase output. Using your smart phone or the optional wireless controller, you can change performance levels on the fly, revert to stock, adjust throttle sensitivity levels, and read/clear fault codes. This upgrade is a plug-and-play unit does not alter the software on your vehicle's factory ECU. Simply plug in, select the output level you want, and enjoy more power! And should you ever want to revert to stock, you can simply unplug the unit from the vehicle! This upgrade is equipped with 5 different performance levels and individual throttle sensitivity adjustments. Using your smart phone, you can fine tune each level, and change them on the fly. Using the optional wireless controller, you can change programs quickly without even using your phone! Fits VW Atlas 24-25, VW Atlas Cross Sport 24-25, VW GTI 22-24