This part will connect 3/16" steel brake lines with 10mm or 3/8" threaded fittings together. The 10mm will work with Datsun 240Z, 260Z, 280Z, 280ZX & 510 brake lines. Use our universal hard brake line that can be hand formed to make virtually any brake line on your car. Choose from 10mm metric fitting or 3/8" SAE fitting.