One of the most common camera lens parts on is the  ring. And there are different kinds of rings,this is a focus ring on the lens body, which moves the lens elements inside the lens. By adjusting the position of the glass elements, the image produced by the lens can be brought into clear focus. Although most modern lenses feature auto-focus, they will usually have a focusing ring to allow for manual control if desired. Each lens that has zoom capability has a focal length ring. This ring allows you to zoom in or zoom out on a subject.
Phone camera lens barrel features:
1.Light weight and bear specific tolerance
2.High impact resistance and  good heat resistance
3.Compatible with 99% mobile phones in the market
4.Quality assurance admitted by many optical tech-giants.