Pn# - TN72 - 10pc OEM Brake Line Fitting for 3/16" or 4.7 MM Tubing, Thread 10mmx1.0, Hex Head 10mm, OAL .630, Length of Thread . Finish Blue Zinc. GM Most Common Metric Fitting. These are exact to the factory originals and have all the details - they are the correct size and shape with the correct color. This is a exact inline tube reproduction of the original. These are the details that separate the first place cars from the rest.