This car alarm is for police,ambulance car use,and some other use with high quality This car alarm's Technical Datas is as below :1.Rated Power80W 2.Rated Voltage: 12V 3.Rated Impedance:4Ω,8Ω 4.Frequency Range: 500-4600Hz 5.Sound Pressure:118-120Db 6.Sound Distortion Factor:≤5% car alarms(YH-100B)