Raybestos EWS37 R-Line Replacement Rear Disc Brake Pad Electronic Wear Sensors are designed to keep you informed about the remaining life of your brake pads. Engineered and tested to meet durability and reliability under extreme conditions, this electronic wear sensor monitors the thickness of your vehicle's pads and sends a signal when the pads have worn beyond their intended service life. Made to OE requirements for fit, form and function, you can be assured your new Raybestos wear sensors will perform equal to or better than the original wear sensors on your vehicle.