Safemate Parking Sensor System,also called the parking distance alert system,is a vehicle safety device that can be installed to any make of car or truck.Safemate will end the guesswork of judging the distance in the blind spots,while backing up or moving forward with your vehicle,to park,regardless of the vehicle's size.Safemate also doubles as a backup alarm,alerting you to anything behind the vehivle while backing up.The system is based on the principle of ultrasonic distance measuring,which consists of three parts:the ultrasonic sensor,computer control module,and the dispaly module.