The Teradek T-RAX Base Rack System comes with a modular Power Supply. But, as with many "open"card or blade systems, this system has been designed with a redundant power supply in mind. T-RAX Base Rack System can support 8 Cards + the included Power Supply or it can support 7 Cards + 2 Power Supplies. A redundant power supply is insurance for when you need it most! It is also a replacement for the original power supply that comes with the T-Rax Base System if it should ever need replacing. T-Rax Power Supply - 460w 1U