... duplex,unlock clear night vision,video,sound 2.4G digital wireless color vedio doorbell Function Feature1) Transmission distance: 300m (free lane)2 ... 2 indoor monitor 2.4G digital wireless color vedio doorbellIndoor Monitor1) Monitor Screen:2.4 inch color screen2) Input :AC100-240v 50-60HZ3 ... CE/ROHS/FCC approvedAccessory screw, rechargeable battery,manual, power adapter wireless vedio doorbell