The Hisonic HS120B seamlessly combines a powerful 40 watts speaker with a UHF wireless microphone system into one portable PA system. The speaker is built-in with a long-life high-capacity lithium rechargeable battery ideal for outdoor activities where there s no access to a wall outlet. When the battery level is low simply plug into a wall outlet with an included power cord to charge it up again. The speaker can also be powered by a power cord and a 12V/DC adapter (included). The system comes with one handheld transmitter/microphone and one body-pack transmitter which can be used with either a headset microphone or a lapel microphone. So you have the convenience of choosing one out of the three microphones to use at a time depending on your application.