Listing is for: (1) High Quality Stainless Steel Ball Bearing & (2) Line Roller Washers.
Offered in this listing is a ball bearing upgrade kit to replace the factory bushing found inside the line roller with an actual ball bearing. These reels do not come with a ball bearing on the line roller but instead they have a cheap plastic bushing in place (see picture below).
This simple an inexpensive modification will make the fishing line run smoother through the line roller. It will drastically reduce line twist, wear, and breakage, which is actually the main reason why fishing reels use a ball bearing on the line roller in the first place.