The TE 6-173977-4 is a 4-position receptacle from the CT series, terminated via IDC onto discrete 26-28 AWG wire.
The 2.00mm pitch matches the footprint of the mating CT header — the board-side pad spacing is fixed by that dimension. IDC termination on discrete wire means each conductor is individually pressed into an insulation-displacement slot, not mass-terminated from a ribbon cable. The 26-28 AWG range is narrow: 24 AWG is too thick to seat, 30 AWG won't be gripped by the slot. Tin contacts are rated for a modest number of mating cycles — fine for a one-time assembly or occasional field service, not for repeated disconnect under a panel.