... more powerful, let you hand, easily build wireless alarm system;4: Alarm linkage function, the first time will alert the ... , clearly visible.6: Exclusive use two-way wireless technology, alarm signals increase 98%;7:Intelligent on-line detection, ... key upgrade,support External interface speakers,support External interface wireless gainModel No.SU-N50Image SensorSensor1/3'' CMOSDisplay Resolution1280x960 ...