Brief: Wall-mounted Video Door Phone with 7-inch TFT LCD Screen and Pinhole Camera Product describe: Four-wire system Screen size: 7-inch TFT LCD Power supply: 18V DC Mount type: wall mounted Dimensions (W x H x D): 230 x 165 x 40mm Available camera: TK-819C Ring bell: music optional Camera: pinhole, zinc alloy, infrared lamp, prevents knocking