The Pyle Megaphone Bullhorn is compact, powerful and portable. With each iteration of flagship megaphones, we've improved the battery life, power, and ergonomics. This model has 20 watts of power, so your voice will reach over 400 yards away. It also features a built-in button-activated siren alarm function, convenient folding hand grip, with a durable design trusted and used by U.S. armed forces. It works great indoors or outdoors.