Top right is a ferrite bead. It is used to cause a high impedance on the exterior of the cord. Often times these cords have a outer shield (think coax). radio frequency can get onto the outer side of the cord's shield and cause interference to the electronic that it is connected to. Tge cord acts like an antenna picking up signals from radio sources. I use them all the time in ham radio for to keep radio interference out of my electronics. Case in point, when i send emails over the ham radio, if my usb does not have one, my laptop messes up and can not recieve the signal to shut down my radio causeing to stay transmitting. And several lights in my house would turn on and off until i installed these on the cords.