ST2060/2060B/2060BC/2120/2120B/2120BC ST2180/2180B/2180BC/2250/2250B/2250BC ST2350/2350B/2350BC 3 MIC inputs , 3 AUX inputs and1 line output Priority microphone with mute-function Treble and bass adjusters 7 segments signal level indication Main volume control and Turn on delay Over current and short circuit protection Over heating and DC offset protection Fault indication SE-B with 6 zoning controller SE-BC with 6 separate zoning volume controllers Build in MP3/SD card Fan cooling control With chime tips Output:100V/70V 4-16ohms Power supply:AC 115V/230V POWER OUTPUT: ST2060(B)(BC) 60W ST2120(B)(BC) 120W ST2180(B)(BC) 180W ST2250(B)(BC) 250W ST2350(B)(BC) 350W