This is a replacement JQ Products Rear Universal Driveshaft Set, and is intended for use with JQ Products THE Car. These universal driveshafts transfer power from the rear differential to the wheels. Other cars use CVD's because they are cheaper to manufacture. But there are many negative aspects to the CVD design. They wear out faster, they are inconsistent over time because they work differently when they are new compared to when they begin to get worn out, they require constant maintenance and use larger bearings and bulkier hubs. That is unless you want to loose coupler pins. Because of these design flaws, universal driveshafts have been chosen for the front and rear of THE Car. This package includes two rear driveshafts.