APC Surge Arrest is the ideal way to keep your electronic devices safe in the event of a power spike or interruption. Protection Lightning & Surge Protection To prevent damage to your equipment from electric power surges & spikes. IEEE let-through ratings & regulatory agency compliance APC surge protectors undergo stringent testing by IEEE, & are awarded "let-through ratings", which indicate the maximum voltage level that can possibly reach your equipment after a surge or voltage spike has passed through an electric surge protector. Lower IEEE let-through ratings indicate better protection & performance. The APC Essential Surge Arrest series offers optimal performance with a let-through rating of less than 330V for North American products, & a rating of less than 15% for products sold worldwide. All APC products comply with local agency safety requirements, including UL in North America & CE/ Kema/ Gost/C-tick/A-Tick/ Telepermit in their respective regions. Noise Filtering Attenuates EMI/RFI line noise that can cause data errors & keyboard lockups, ensuring better performance of protected equipment. Safety Catastrophic Event Protection Surge Arrest components such as MOVs & Thermal fuse ensure instantaneous reaction to lightning strikes & wiring faults. If the surge components are damaged due to power spike or over voltage, excess power cannot reach your equipment. Unlike the APC Surge Arrest products, most surge suppressors continue to let power through even after circuits have been damaged, leaving your equipment exposed to other damaging surges. 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 Surge Arrest fail safe, which means that once the circuit of an APC Surge Arrest has been compromised the unit disconnects equipment from the power supply ensuring that no damaging surges reach your equipment. Protection Working Indicator Surge Arrest will warn you if its circuitry has been damaged by heavy strike or power line surge & it is unable to provide 100% protection. If still under warranty, APC will then replace your damaged Surge Arrest free of charge. Building Wiring Fault Indicator This LED informs users of potentially dangerous wiring problems in the wall circuit.