This Power Over eSATA to SATA 22pin cable enables you to connect your 2.5" or 3.5" SATA HDD externally to any free Power Over eSATA (eSATAp) port. The Power Over eSATA port combines eSATA and USB and enables the power supply of 5V via the integrated USB interface. Thus you do not require any additional power supply for a 2.5" HDD. For operation of a 3.5" HDD just connect the molex-connector to a power supply.