1、2 Way Audio: Support two way talk communication, when you hear your baby's cry, you can quickly soothe your baby with the baby monitor with clear sound quality. 2、Night Vision: The baby monitor has a high resolution night vision function that enables 24 hour monitoring, and the night vision function allows you to see your cute baby at night. 3、Vox Auto Wake Function: If the baby's volume reaches a certain level, the monitor will be triggered. (The monitor will automatically activate from the screen saver mode) to notify the parents to check the baby's condition. 4、Characteristic: Using 4GHz wireless transmission frequency, in line with FCC, CE standards, high resolution 4in LCD display, support long range transmission, maximum 200‑300m/218.7‑328.1yd in open area, 5、4 in 1 Connection: Video baby monitor supports 4 in 1 connection, you can connect 4 cameras with one monitor, the monitor uses lithium battery, which provides convenience for mobile use. 1 x Camera1 x Monitor2 x Power Adapter2 x Expansion Tube2 x Screw1 x Manual Item Type: Baby MonitorMaterial: ABSScreen Size: 2.4in LCD DisplayScreen Resolution: 320x240 RGBImage Resolution: 320x240 QVGAVideo Frame Rate: 15-25FPSSignal Strength: Level 4Volume Control: Level 5Walkie Talkie: 2 Way CommunicationVoice Control: AutomaticTransmission Frequency: 2.4GHz ISM BandHow Wireless Works: FHSSTransmission Power: 19dBm CW ModeTransmission Speed: 3MbpsTransmission Range: Approx. 200-300m/ 218.7- 328.1yd in Open AreaWorking Current: TX: 400mA MAX.Receive Sensitivity: -96dBm BER=1e-3Charging Current: 120-200MAAudio Catch Speed: 16KAudio Frequency Response Range: 120Hz - 3KHzMIC Input: 35-50dBTotal Harmonic Distortion: < 5.0Signal To Noise Ratio: 46dBNoise Ratio at Night: Approx. 2-3 Meters / 6.6- 9.8ftWorking Humidity: 20 - 80%RHWorking Temperature: 0℃ - 45℃Battery Type: 750mAh Lithium Battery x 1 (Built in)Plug Voltage: AC100-240V