Noise Filtering - Attenuates EMI/RFI line noise that can cause data errors and keyboard lockups, ensuring better performance of protected equipment. Resettable circuit breaker - Easy recovery from overloads; no need to replace a fuse. (Not available on Wall Tap SKUs) Status Indicator LED's - LED status indicators for each phase and an audible alarm provide immediate failure notification when surge suppression circuitry has been damaged by a heavy strike or surge. Catastrophic Event Protection - SurgeArrest components such as MOVs and Thermal fuse ensure instantaneous reaction to lightning strikes and wiring faults. If the surge components are damaged due to power spike or over voltage, excess power cannot reach your equipment. Unlike the APC SurgeArrest products, most surge suppressors continue to let power through even after circuits have been damaged, leaving your equipment exposed to other damaging surges. Building Wiring Fault Indicator - Immediately warns you of wiring problems like improper grounds that could cause shocks or prevent adequately suppressing surges. IEEE let-through rating and UL 1449 compliance - The 'Institute of Electrical and Electronics Engineers' (IEEE) Let-Through Voltage rating is based on a test that subjects a Surge Protector to a 6,000 volt spike. The rating equates to the amount of excess voltage that reaches connected equipment. The lower the number, the better the performance of the Surge Protector is. Underwriter's Laboratory's UL1449 surge protection safety standard uses these ratings to help users gauge performance. UL's best Transient Voltage Surge Suppressor (TVSS) Let-Through Voltage rating is "300V". Fail Safe Mode - Most other surge suppressors continue to let power through even after their circuits have been damaged, leaving your equipment exposed to future surges. APC's SurgeArrest fail safe, which means that once the circuit of an APC SurgeArrest has been compromised the unit disconnects equipment from the power supply ensuring that no damaging surges reach your equipment.