This power supply is a compatible replacement for Bestec part number TFX0250D5W REV X4 power supplies. If you own a Bestec part number TFX0250D5W REV X4 this TFX0250D5W power supply will fit without modification. We also offer this power supply upgrade that will replace your Bestec part number TFX0250D5W REV X4 power supply.