Product line with my expectations. After reading reviews on Amazon.com, I decided to buy this product because I wanted to connect an external hard drive permanently to perform backups on a usb port on my PC. Done. The D-Link hub works only independently supplied with power via the USB socket on the PC. Use: typical desktop PC with tower, 19-inch screen and printer, I do not need to connect it to the power outlet. And my external hard drive operates at the hub without problems so far. As always the adapter comes with a power cable too short. But I do not need. I recommend this product. He does his job.