This HS919 (JP919) complete portable lapel / lavaliere wireless microphone system and is fantastic for a variety of applications and uses where the spoken voice needs amplification when you are in the following environment: classrooms, swap meets, trade shows, scout meetings, public speeches, general meetings, bingo... etc. This system is perfect where 110 volt power is not available or not easily obtained. Since the wireless microphone system, FM receiver are all battery powered you will not be at the mercy of the wall plug.