Brakequip Fitting - Male M12X1 (LONG)

This Brakequip fitting features a male M12X1 connection in a long configuration, so you'll want to double-check that matches the specs for your Mustang's brake lines.

Correct on both counts. M12 is the outer diameter in millimeters and the 1 refers to a 1mm thread pitch, which puts it in the metric fine pitch category. That matters when you're matching it to a port or hose end, so double-check your mating component carries the same spec before you wrench it down.