Dual USB cable for Passport Essential

I’m looking for a Dual USB cable for Passport Essential (USB3) as my laptop seems to be weak in power.

Where can I find in US?

Thanks,

RON C

Try Google.com

Spent a very long time on Google with no success. 

Tried again and found this on Brit site: 

AA2USBPC  Dual USB power input adapter cable. Combines the power of 2 USB ports into one.  Addonics part reference: AA2USBPC

Saw reference to Addonics and found there.

Thanks,

RON C