Model : TSU-100T (100W) Input voltage: 100V die- cast aluminum , built-in transformer can adjust the input power DRIVER UNIT Model: TSU-100T Input power: 100W input voltage: 100V Frequency resp.: 180-6000HzS.P.L.: (1W/m):110dBDimensions: 170*170 mm die cast aluminum ,built-in transfomer , can adjust the power can be mounetd with the horn bell directly