The Shuttle XPC Accessory PC850 is an internal AC to DC switching power supply unit (PSU) meant as upgrade kit for certain Shuttle products. This power supply is guaranteed to deliver an excess of power for power-hungry processors and graphics cards. It provides a maximum output wattage of 850 Watt. Its 80 PLUS® Platinum and Energy Star V5.0 compliance helps save on energy costs as compared to previous power supply models.