The Babymoov Expert Care Baby Monitor has a range of 1000m & is voice activated to limit the waves emission. The Expert Cares other features include 16 channels & an out of range alarm & battery low alarm. Powered by a long life lithium battery, you have the option to choose how the alarms work, either acoustic, visual or vibration. Technical Features Emission Power: 5-10 m W Frequency: 865 MHz Powered by rechargable Lithium batteries (parents unit) & 3 AAA batteries (Babys unit) or mains operated (adapters included)