The PMP53IN is a power horn speaker/megaphone capable of projecting your voice in superb clarity - up to a mile! It's perfect when you need to be heard indoors or outdoors in front of a large crowd. Get your voice to the right level with the variable volume control. Or use the built-in siren to get everyone's attention. You can even plug in an external audio device, like an iPod or iPhone, using the 3.5mm jack. Pyle's megaphones are built with a tough housing and are used by the U.S. Army, schools, sports coaches, and more. Requires 8 C batteries, not included.