4mm Lined End CapsIdeal for Shimano Derailleur Lined end caps have an internal sleeve that extends out from the end. This liner protects the inner cable from the opening in the end cap, preventing cable coatings from wearing off and ensuring the lowest possible friction. Lined end caps can also be paired with a sealing liner or a dirt guard to keep dirt and grime out of the housing. Attributes Ferrule Diameter 4mm Material Alloy Primary Color Black