I chose because of the switch for this USB hub. As my Raspberry Pi's about no on / off feature, the switch for this purpose are very practical. So to provide RPi's electricity works before, that was it but also already. Not a single, connected to the hub, the USB device is recognized. Neither card reader nor USB sticks, or hard drives. I tested on 3 different Rasberry Pi B +, always with the same result. I use this USB Hub now practically a power strip to my Pi's to supply with electricity. This I save two power supplies. For its intended purpose, this USB Hub for me can not use unfortunately. What I also noticed negative, that's very short USB cable. Once you make your PC are under the table, the cable is hardly sufficient in length to.