Dual-Pitch IDC Header for Ribbon Cable
The 1658525-9: The cable-side pitch is 0.050" (1.27mm), which means the header accepts standard 20-conductor 1.27mm-pitch ribbon cable and fans it out to the wider 2.54mm board footprint — a common transition for prototyping or production wiring where a DIP socket or through-hole pattern is already laid out.
The header terminates ribbon cable via IDC (Insulation Displacement Connection), accepting 26-28 AWG stranded or solid conductors. This is a one-time termination; the header is not designed for repeated re-termination. The through-hole pins insert into a 0.100" pitch board pattern and are soldered on the opposite side.
The blue housing and bulk packaging are as listed.