This voice projector is an over the shoulder portable PA. It provides 15 Watts of amplification with excellent voice reproduction. It operates on 8 C size batteries or it can be used with the TT125 AC Adapter. It has a detachable microphone or it can be used with the Tortech HA-11 headset. The VP 15 is popular for police, fire departments, schools, events, guides, sporting events and crowd control.