128X128LCM LCD screen Can call every Indoor Phone. In the meantime, it can transmit the images to every Indoor phone, and dual talking is availabler. release the electronic control lock by door station with instruction from Indoor phone and, Can call Guard Centre. At the meantime, it can transmit the image to Guard Centre. (video network), and dual talking with Guard Centre is availabler.Individual password is available if needed.(password is in 8 digitals). Unlock can be done by IC card or password.