... a multi-2.4G digital wireless audio and video transceiverintercom, which is our patent product, R&D by our company .It adaptslong ... chip,with a little amount of external components, such as audio amplifier,microphone, speakers, etc. Also adopt industrial-level design standards ... /h,3.7V Charging voltage limit is 5v2) Charger: Input AC voltage 110V-240V, 50/60Hz Output 5V/1A passed by ...