TweakTown posted a review on the Ultra X4 1600 Watt Full Modular Power Supply

Power supplies are important and often overlooked components. Ultra Products understands that case-proud PC enthusiasts do not overlook the PSU. In fact, hard-core hardware geeks demand not just performance, but style to complement not just their ass kicking hardware, but their beautifully lit cases. Thus, Ultra has released the new X4 Series in a range of wattages starting at 500 watts. The model we are taking to task in this review is the totally modular 1600-watt version.

This block of power weighs a respectable 15 pounds, measures 240mm x 150mm X 87mm and features a 135mm fan. And, it is 80 Plus Certified. One note about the 1600-watt rating; this PSU is rated at 1600 watts when connected to a 20-amp plug using the special 120 volt 20 AMP cable (included). When you use the included 120 volt 15 AMP cord to connect to a typical outlet, the PSU operates at 1200 watts.

Ultra X4 1600 Watt Full Modular Power Supply Review