The AN thread is a particular type of fitting used to connect flexible hoses and rigid metal tubing that carry fluid. It became popular for usage within Professional racing for the ability to easily customize new lines. From there it's usage spread to the aftermarket automotive performance field for its ease in adaptability, upgradability and durability.
Style: 90 Degree Swivel Extended End Adapter
Fitting Size: 4AN
Professional Installer is Highly Recommended (No Instruction Included)