Steel Brake System Adapter, -03 Male JIC 37 deg Flare To 10mm x 1 Male Metric Flare, Straight

That's the kind of job this part handles. One end is a -03 Male JIC 37 degree flare, the other is 10mm x 1 Male Metric flare, and it runs straight through with no bends or offsets. It's made by Eaton Aeroquip, part number FBM2941, also cataloged as C1EB74. Steel construction, so it holds up in brake circuit environments where thread integrity and a solid seal matter. If those two thread forms match what you're working with, this is a direct inline solution.

This steel brake adapter is designed to adapt a -03 Male JIC 37° flare to a 10mm x 1 Male Metric flare. It's a straight fitting, so it provides an inline connection between those two thread types.

For a straight, inline transition between those two flare standards, that is exactly what this fitting is made for. It has a -03 male JIC 37 degree flare on one side and a 10mm x 1 male metric flare on the other, so it is meant to bridge JIC to metric in a hydraulic brake circuit.