Black, white or red rectangular-shaped resin pieces screw into your cable ends to hold a current project while using the tips for another project. White [S] end stoppers fit onto all [S] coded cables. Black [L] end stoppers fit onto all [L] coded cables. Red end stoppers fit onto all MINI TWIST cables.
This is fabulous yarn to work with. I have been making hats with this yarn and they are so light and soft. Definitely worth finding a project to work with this yarn.