It will fit in a standard ATX power supply slot, but just won't extend out as deep as a more traditional ATX PSU. These replacement power suppplies can replace many branded desktops like HPs, Dells, Compaqs, etc). It is cooled by an 80mm fan for stability and long-life performance for years to come. The power supply has cabling built in to give you access to SATA, Molex and Floppy disk drive power connectors, as well as a 20+4-pin motherboard connector, and 4-pin CPU. Max Wattage: 420 Watts Total Wattage: 280 Watts Reduced Depth for Increased Compatibility AC Input: 110/220V / 47~63HZ Hi-Pot Tested Low Ripple & Noise ROHS & CE Frequency: 60/50 Hz Rise time: Less than 70 ms Hold-up Time: 17 ms Minimum at Nominal Input Voltage Output Voltage: +5V,-5V,+12V1,+12V2,+3.3V,-12V,+5V-SB Dimensions: 5.86" x 3.3" Connectors: ATX Connector 24 (20+4) Pin x 1 P4-12V 4 Pin x 1 SATA 15 Pin x 3 Molex 4 Pin x 2 Floppy 4 Pin x 1