You can use the USB ports in addition to two- and three-prong power plugs. Lastly, the outlet's built-in USB charger may not fit in shallow electrical boxes, so confirm that it's compatible by ...
“With the cable unplugging ... this is still a great charger, and i brought it with me on a trip to Japan! Only thing is most of Japan uses a 2-prong plug, and this comes with a 3-prong plug!