Zalman ZM400A-APF 400-Watt Noiseless Power Supply Noise-free 400-watt ATX (version 2.03)/ATX12V power supply supporting Intel Pentium 4 and AMD CPUs Heat-sensor circuitry controls the cooling fan's speed Can be used with any normal AC input source ranging from 100VAC to 240VAC By implementing Active PFC, the power factor is improved from 75% (Passive PFC) to 94% (at full load) High switching frequency and low power-loss circuitry