The Pyle PMP38R is a professional 30 W megaphone/bullhorn. With each iteration of their flagship megaphones, Pyle has improved the battery life, power and ergonomics. The lithium battery provides long-lasting power and saves money on batteries. This model has 30 watts of power, so your voice will be heard from 800 yards away: that's almost half a mile. The PMP38R is equipped with a 10 second memory - perfect if you need to broadcast the same message repeatedly. And if you simply need to get everyone's attention, switch to the siren mode to activate a loud, powerful alarm sound. It works great for indoors or outdoors.