HP 720478-B21, 500 W, 100 - 240 V, 94%, Server, Flex ATX, 80 PLUS Platinum HP 720478-B21. Total power: 500 W, AC input voltage: 100 - 240 V, Efficiency: 94%. Purpose: Server, Power supply unit (PSU) form factor: Flex ATX, 80 PLUS certification: 80 PLUS Platinum. Product color: Metallic. Width: 2.68" (68 mm), Depth: 1.59" (40.4 mm), Height: 8.87" (225.3 mm)