Jagwire 4mm Sealed Alloy End Cap For Outer Cable Shifter, Black BOT057BJ Description High-quality sealed aluminum end cap with a diameter of 4 mm, black anodized, Jagwire logo. An internal rubber O-ring helps keep the Bowden cable clean and dry. You can use these end caps if you want to protect against dirt, but at the same time you want to keep friction to a minimum in areas such as frame stops. Material: Aluminium Color: black