CE,ROHS,ISO9001 Approved. High sound level. 1.Operating Voltage:24V2.Coil Resistance:19Ω±10%3.Frequency Range:2500Hz±20% 4.Impedance (at 1 KHz): ≥70Ω5.SPL(1M,1KHz,24Vp-p):≥90dB6.OTHER COIL RESISTANCE IS AVAILABLE7. Dimensions: 8.Frequency Response Curve siren transducer