It's just an OEM. This is the power supply's info pulled off of HP's website:
Internal 460W (100V-240V)
Form Factor: internal ATX
Total wattage: 460W
Nominal input voltage range:
Dimensions: 150mm x 140mm x 86mm (5.9 x 5.5 x 3.4 inches)
* This power supply has an LED to indicate a possible failure condition when LED is off and power is connected.