What This MTA-156 Receptacle Is For
The 4-640601-2: The 0.156" (3.96mm) pitch is the standard spacing for this series; if your board has a mating header at that pitch, this is the half that drops onto the wire harness.
Termination and Field Fit
IDC termination on 22 AWG wire — the insulation is displaced as the contact is pressed home, so the wire prep is just a square cut. The red housing colour is a visual key for the wire gauge; MTA-156 receptacles in other colours indicate different wire sizes. Free-hanging (in-line) mounting means it floats in the harness, not on the board — the strain relief is on the cable side. If you are re-pinning a failed connector on site, this crosses into the harness you have as long as the mating header is MTA-156 at 0.156" pitch.