... .5 inch wireless video door phone intercom system 1.3.5 color LCD display 2.hands-free calls 3.300meters 3.5 inch Wireless video door phone intercom system 1 ... 0-9 grade. (4) Melodies and Volume:Under the bright screen condition, press twice “Monitor” button enter to Ring operating, ... to “ON” position, display will light,approximately 30S into the screen off standby; “ON” key to the OFF position, enter ...