Features: Surface-mounted, 7 Inch color TFT Screen with sensor buttons Color/contrast/brightness/volume adjustable Intercom, broadcast, Call transfer among indoor monitors Supports 2 Outdoor Units to work with 4 indoor monitors Different indoor monitors can supervise different channels or the same channel at the same time Support visitor-calls transferable to telephone Support door released by telephone remotely or any indoor monitors Support image capture function 64 images memory Support insert SD Card for saving captures images to computer for history record Support 4-Channel CCTV cameras fitted for security surveillance Support watch TV & Listen music function Applicable for Villa 4 wires twisted pair cables, simple star cable installation Technical parameters: Display screen 7 inch TFT Resolution > 400 TV lines Scan frequency 15, 625Hz(H)*50Hz(V) Power voltage AC 110~220V 1200mA Video input 75Ω 1Vp-p Power consumption 1.5w ~12 w Wiring mode 4 wires, polar Ambient temperature -10oC~40oC Dimension 260(W)*195(H)*35(D)