Ring cable lug | crimp cable lug ring shape
Ring cable lugs (also known as ring-shaped crimp terminals) are used for earthing cables or in the car hi-fi sector, for example. Ring cable lugs enable clamping contact to be made on electrically conductive components. In particular, by enclosing a screw that is connected to an electrically conductive component and by screwing it in, the cable lug(s) are clamped.
For more information on ring cable lugs and their processing, see here.