... -GPS (LBS—location based service)12. LED Advertising Screen, RS232 Printer, Temperature sensor, RFID (optional) Positioning and tracking: ... )Other is extending ports, can connect to LED screen.Microphone3.5mm single trackearphone3.5mmCurrentNot working Current ... GSM antenna, Engine controller, SOS button, Microphone, Camera, LED advertising display(optional) Application Area :Taxi companies, Passenger ...