Replace Power&reg; 400W 400 Watt ATX Power Supply Replacement for HP Bestec ATX-250-12E, ATX-300-12E, ATX-300-12E-D Replaces Several Older Legacy Power Supply; Upgrade to 400 Watts Built-in 20+4 Pin Adapter: Supports 24 and 20 Pin Power Supplies Reduced Depth for Increased Compatibility; 5.9" Height x 3.4" Weidth x 4" Depth Over Current and Over Power Protection; Over Voltage and Short Circuit Protection 110-260V AC Switchable Power Supply