... night vision 4: ultrathin monitor new style 7 inch TFT color video door phone intercom systems Model:SMT-V7I- ... .6 LED lights,nightvision.**handfree indoor monitor, 7 inch TFT,clear image.** intercommunication,monitoring the outdoor,unlock..** Intercommunication is ... rings for option.**two cameras can connected with four monitors.(different choice)**four wires,DIY installation**Including in one ...