The berry Classic Audio Baby Monitor The Classic Analogue Baby Monitor allows you to stay connected to and hear your baby at all times. The LED on the mother unit gradually lights up as the intensity of the sound coming from the baby increases. When you set the activated sound, the mother unit will only be activated in the presence of sounds detected by the baby. 2 channels are available to ensure communication between the two units and minimize interference. Both units (parent and baby) can be operated on battery or AC adapter. Technical information including 2 network adapters and 3 rechargeable Ni-MH AAA batteries for the mother unit.