JISTL 30cm USB 2.0 a Power Enhancer Y 1 Female to 2 Male Data Charge Cable Extension Cord(pack of 2)

If you have a device that draws <1.0A of current and you've got two USB ports that only give you 500mA, this will work perfectly for you (and I'd give a 5-star rating if that was the case for me). However I have a device that needs 1.5A and the wires in this power Y-combiner adds enough series resistance to reduce the current compared to just my single (3A "rated") USB cable.