Posted by Marc Martin on
URL: https://www.es-forum.com/Ferrite-Rings-for-corded-mouse-keyboard-tp4036474p4036485.html

Yes, 2-prong is ungrounded.  Although you can buy a special USB cable to ground it.  Or if your ethernet is grounded, then that could also ground it.  Although you don't want to ground it more than once, as you could set up a ground loop (potentially)