Real-time baby monitoring via sound; With yellow night light; The night lamp will be ON as long as the voice from the baby comes, the bigger the voice, the brighter the light; With lullaby to help the baby go on sleep more quickly and stabler; Built-in high capacity Li-ion battery for 20 hours' continuous work; Transmitting distance: 300m (in open area); With adjustable voice; 3.7V 400mAh battery; Frequency: 2.4GHz.