Megaphones with sirens rvfm 952016 a powerful and durable megaphone that is suitable for all outdoor occasions its built in powerful 25w amplifier and high quality anti feedback microphone can project a clear sound up to a distance of 1km depending upon conditions the microphone also features a handy push to talk switch and rotary volume control and is made from strong abs with a rubber edge protector having a built in siren means that this versatile loudhailer can be used either as a voi