This cable does exactly what it should: it combines a SATA disk to the eSATA port of my laptop. The power is supplied via an external power supply that I use a SATA - acquired> USB connection kit. It conforms to the standard, there is nothing too great, as is alleged in another review.
Meanwhile, I was able to test the cable to external hard drives from Iomega and WD. Both hard drives the cable fünktioniert properly.