Panamax surge protectors use SurgeGate technology. Competing brands claim to disconnect power if their surge rating is exceeded. This is partially true. What usually happens is that the part circuitry is disconnected, but dangerous over-voltages can still get through. Not with Panamax. The Joule rating is irrelevant with the SurgeGate circuit which creates a barrier between the surge and your investment. SurgeGate technology also means the surge protector has a very long life, as does the warranty on most Panamax products. The surge protector is not set up to "sacrifice itself"as most protectors are. If series mode protectors come to mind, you might want to think twice. The coil technology found in these devices fail when protecting connections from prolonged power surges. If you are in areas where this might occur, such as in colder regions where ice storms can devastate an area for many hours, then this product might be the choice for you. SurgeGate technology keeps a Panamax surge protector in the best shape, all the time.