... Microphone, Karaoke Microphone, UHF Wireless Microphone, Professional Microphone, Mic, Wireless Mic, PA Mic Wireless Microphone, Karaoke Wireless Microphone, UHF Wireless Microphone, Professional Microphone, ... circuit * Manufactured by SMT components and technics * AA size batteries for microphone, supply time up to ... DC-DC step up circuit design for microphone * Up to 300 meter operation distance ...