This advanced monitoring and alert system detects abnormal tire conditions and will display the status and alert you to take action when needed. It will keep you safer, extend the life of your tires and improve fuel efficiency. System includes four sensors and a receiver unit. You can even install it yourself – no professional installation is required. The four wireless transmitters simply screw into the tire valve stems. The dashboard display/receiver is easy to read and emits an audible alarm for unsafe tire conditions. Includes 12-volt power adapter and transmitter installation tool.