With each iteration of flagship megaphones we ve improved the battery life power and ergonomics. This model has 25 watts of power so your voice will have a range of 1200 yards. Comes equipped with built-in SD & USB flash memory card readers rechargeable lithium battery with charger and the 3.5mm Aux-In jack allows you to connect and play your MP3 smartphone or other external device and stream audio directly through the megaphone Works great indoors and outdoors.