... 4monitorsBoth outdoor and indoor unit with battery to workDescription :2.4Ghz frequency,wireless transmission range is up to 350meters without ... to more than monitors can be done.1to 1,1to 2,1to3,1to 4 are available .Monitor color available: grey ... 60HZOutput powerDC 12V; 1ABattery3.7V,1000Mah li-batteryPowerStandby :0.2W,Unlock:12WWireless transmitting rangeUp to 350 meters in open airWorking ...