The PMP43IN is a power horn speaker/megaphone capable of projecting your voice in superb clarity - up to 1000 yards! 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 6 D batteries, not included.