... open area two-way speak, receiver and camera talk to each other Built-in rechargeable Li-battery lasts for 3 ... of use, extra safety for baby, helping Mommy let baby learn to sleep on her own, price range, private frequency, dependability ... SignalVideo, AudioTransmission Frequency2.400GHz~2.480GHz Open Transmission DistanceUp to 150meterPower DC5V/1.5A Working Temperature-20~60°CPower Consumption ...