20W power; Over 400-yard range; Used by US Armed Forices; 2 audio functions: voice & siren modes; Compact & durable with foldable handle; Ergonomic pistol grip & lightweight chassis; Voice mode amplifies voice as spoken into microphone; Alarm mode amplifies alert/siren tone through the megaphone speaker; Requires 4 C batteries; Dim: 5.4 dia x 8.6L;