TM-7900 Operating Voltage Range: 10.8-16VDC(max: 1A) Input Voltage:12VDC InputCurrent:0.7A Grouding system:car battery negative pole Dimentions:181X119.3X25mm(L X W X H) Operating Humidity 45% to 80% RH Storing Humidity 30% to 90% RH Video Signal Input Level:1.0?.2V P-P Video Signal Input Impedabce 75 Ώ Audio Signal Input Leve 12.0 V rms Audio Signal Input Impedance:10 k Ώ Audio Signal Output Impedance:16 Ώ or 32Ώ Earpieces Output Power:0.25W X 2or 0.125W X 2 Display Monitor Specification Screen Disgonal Length:7" Usable Display Area:154.1mm(W) X 87.0mm(H) Viewing Angle:65℃ from the bottom 40℃ from the top ?5℃ horizontally