3.5 inch Wireless Digital Intercom System Wireless Gate Doorbell Waterproof outdoor camera,use it outside 3.5" Wireless digital video door phone ... function ,record the pictures of visitorsAlarm function,anti-steal Wireless ,no need wire cable Both wall-mount and desktop ... unit with battery to work Description :2.4Ghz frequency,wireless transmission range is up to 350meters without obstructions.Indoor ...