The PowerStop Disc Brake Pad Wear Sensors Kit includes two brake pad wear sensors, one for the front and one for the rear. These sensors are direct replacements and are designed to fit perfectly with your vehicle's brake system. The manufacturer part numbers for the sensors are SW-1524 for the front and SW-1525 for the rear. Made in Germany, these sensors are of high quality.  I purchased these for our 2008 Land Rover LR-3 before realizing that they were included in the PowerStop brake and rotor kit that I had also purchased.  They are brand new and unused.