Connects 5/16" Domestic port to a 1/4? Domestic brake system. AGS 8" adapter brake lines allow dissimilar connections to be made within the same system. Adapter lines are available in common brake line tube sizes. Poly-Armour has become the new standard in brake line replacement over the last several years. Surpassing all competitors as THE choice for both professionals and do-it-yourselfers when it comes to brake, fuel, and transmission line repair, Poly-Armour is different from anything else on the market due to its PVF or Poly-Vinyl Fluorine coat. This coating is actually a highly durable ‘plastic’ coating that is ‘baked and cured’ to the line. This provides extra protection from corrosion, debris, and road surfacing solutions. It also offers superior bend-ability without kinking. That makes Poly-Armour the easiest line to work with – period! Underneath the PVF-coating is a double-wall, low carbon steel, copper brazed tubing which meets all international and U.S. requirements for brake tubing. The difference being that Poly-Armour offers 30 times the corrosion resistance of galvanized steel alone. PVF-coated lines are now the standard in many vehicles on the road today including: Volkswagen/Audi, Honda, Toyota, and Mercedes. Considered a premium line, Poly-Armour should be used on any vehicle that will see any type of harsh environment including snow, road treatments, salt, air, dirt/gravel, etc. When extending the life of the lines is important, Poly-Armour should be used; such as on commercial vehicles or when exact OEM replacement is required or desired. – Poly-Armour is 30x More Resistant to Corrosion – DOT Approved for Hydraulic Brake Systems – Bends Easier than Standard Steel Tubing – Available in Coils of 25' and 50' – Finished Lines Available for Domestic & Import. Poly-Armour lines and tubing meet the following specifications: SAEJ527b, GM123M, SAEJ1290, DIN 74234