... garrison and arming View storage and information releasing are optional 3.5/4-inch color LCD With the function of video ... talk-back, unlocking by remote control, monitoring Door-stationIn case of emergency, calling management center at any timeWith ... ,625±400HZ V: 47±3HZ Display color TFT: 3.5/4inchMaterial of frameABS Color hands-free door entry 3.5",4"TFT kit "L"