SY-15UA Alu Basket SY-15A Steel Basket Woofer: 15",Paper Cone Tweeter: Compression Driver,44mm Ti Diaphragm 8Ohm,40W Freq.Resp: 40Hz-20KHz Rms/Max: 180/360Watts Voltage: 110/230V/AC/60-50Hz SY-15U Alu Basket SY-15 Steel Basket Woofer: 15",Paper Cone Tweeter: Compression Driver,44mm Ti Diaphragm 8Ohm,40W Freq.Resp: 40Hz-20KHz Rms/Max: 180/360Watts