Legit Reviews posted a review on the Arctic Cooling Fusion 550RF ATX Power Supply

The Fusion 550RF is manufactured by Seasonic for Arctic Cooling and it is internally identical to Corsair VX450W and Antec Earthwatts 500W power supplies. The strange thing about these internally identical power supplies is that the Wattage power ratings are all different. Between the three companies a 100W rating difference is observed, which is pretty crazy no matter where you live or with whom your brand loyalty lies. After a little bit of research it appears that Arctic Cooling rated their power supply at 550W due to that being the peak power rating. This is not something we ever like to see as most other name brand companies don't rate their power supplies like this. The power supply label on the Fusion 550RF says that it can handle 550W loads for a maximum of one full second, so when shopping for power supplies this one is more in the range of a competitor's 450W-500W power supply...

Arctic Cooling Fusion 550RF ATX Power Supply Review