It is convenient for installtion,rich in function,and easy to operate,widely used in domestic and aboard buses system. Support 2 groups audios videos input,Support using key switch monitor channel,one of the group support video auto detect funtion,can be used in vehicles drive back off monitor the door state. Internal RFID swiping card function,applied to driver sign in,the sign in information can be upload to platform for recording through GPRS net. External megaphone achieve in or out of vehicle calls. Support TTS and real body mixed broadcasting,no need record broadcast audios. Support vehicles position real time examination,information release,talk hands-free intercom function.