Panamax surge protectors use SurgeGate technology. Competing brands claim to disconnect power if their surge rating is exceeded. Well, this is sort of true. What usually happens is their own circuitry is disconnected, but dangerous over-voltages can still get through. Not with Panamax. The Joule rating is unimportant with the SurgeGate circuit. Also, SurgeGate technology means the surge protector has a very long life, thus the lifetime warranty on most Panamax products. The surge protector is not set up to "sacrifice itself"as most of them are. If you are thinking series mode protector, think again, they use a coil, and coils pass voltage through during prolonged surges (Won't happen? Ever hear of an ice storm?). Finally, most any UPS will also die during a prolonged surge as they have no protection against it. SurgeGate technology keeps a Panamax surge protector working even during a prolonged surge.