You are able to listen through thin walls, doors, windows, etc. Highly sensitive preamplifier with microphone capsule and headphone. To be used for observing animals (e.g. mice), as baby-alarm etc. UB: 9 V/DC. Operating voltage 9 V/DC Power consumption < 100 mA Output power max. 0.5 W at 8 ohm loudspeaker Size of board approx. 57 x 57 mm