The Superior Surge Protector meets or exceeds the following industry standards: UL 1449 2cnd edition protection rating 400V on all lines for TVSS (Transient Voltage Surge Suppresser), UL 497A standard for phone line surge suppression, UL 1363 standard for temporary power taps. The Indicator Lights lets you know your equipment is protected. All surge suppressers are eroded by every surge they absorb. When this unit has absorbed its capacity to protect, the Indicator Light will go out and the unit will stop conducting power. This assures you that if you have power you have protection.SPECIFICATIONS:AC Line Protection:Electrical Rating:125V, 60Hz, 15A, 1875WJoule Rating:1500J (8x20 mircosecond waveform)Max Surge Clamping Voltage:330 VoltsMax Spike Current:39,000 AmpsMax Surge Pulse Voltage:6000VResponse Time:Faster than 1 nanosecondEMI/RFI Noise Rejection:4 to 52dB from 100KHz to 50MHzOverload Protection:125V/ 15A circuit breakerPhone/Modem Protection:Evaluated to UL497AClamping Level:350VEnergy Dissipation:120JCoaxial/Cable Protection:Yes