dry cell operation all abs body, sturdy yet light weight built –in siren clear sound, long range & efficient design conveniently located volume control & switch specificationspower output: 50w rated / 100w max voice range: 0.7 km power source: 8x“d”(um-1) cells working voltage: dc 12v battery life: 8-10 hrs. microphone: unidirectional dimensions: horn dia.230mm, length350mm weight: 1.5 kg without cells