The unit consists of ac soleniod and electronic control circuit. The soleniod is fixfd to the door lock. The electronic control circuit and switch is fixed at a suitable location. A door phone is also fixed along with this unit. When a visitor rings the bell, the person inside flat indentifies the visitor by speaking through door phone. When the identity is established he presses the button which activates the soleniod & the door gets opened. A visual/ audible signal is provided for indicating that the door is opened. The beeping sound stops & led goes off when the door is closed. A wireless remote can also be provided for opening the door. The unit can also be operated from a epbx. Additional closed circuit camera can also be provided to view the visitor