The Auna megaphone will help you to effectively coordinate large crowds of people at sporting events, at lectures, or at demonstrations & large gatherings. The built-in condenser microphone makes the megaphone very easy to use, & the built in siren can easily grab the attention of everyone in the area. 25W of power extends the radius in which your voice can be heard up to 600 meters. The key advantages of the device are its lightweight, ergonomic design & the convenient strap. The device can be powered via batteries & consumes very low amounts of energy, allowing you to use the megaphone over long periods of time. The battery compartment of megaphone is weatherproof & rain resistant.