Megaphones with Sirens - Adastra 952.019, A 30W, durable, pistol grip megaphone for outdoor voice reinforcement applications. With features such as anti-feedback microphone which can be attached to the megaphone or handheld, switchable siren function and a robust ABS construction make this loudhailer ideal for use, either handheld or shoulder strap operation, in a wide variety of applications.