Athena AP-MPS3ATX40 400 Watt Power Supply Micro PS3 20+4 pin 400W PSU Genuine Fits lots of Dell and HP systems Fits in tight spaces - only 4 inches deep Replacement for Dell Dimension 8300, Dell Precision 360, and Dell part numbers U2832, X2016, W2956, W2955 Athena AP-MPS3ATX40