The 3-647168-3 is a 3-position, single-row header from the MTA-100 series, pitched at 0.100" (2.54 mm) — the same footprint as the classic 0.100" breadboard grid. It mates with MTA-100 IDC receptacles and crimp-socket housings that share the same pitch and single-row layout. The friction lock provides positive retention against casual vibration or cable tug; it is not a secondary-lock TPA, so the terminal retention relies on the receptacle's own lance.
The solder posts are tin-finished, which is compatible with standard SAC305 solder profiles on the SMD pads.
For a typical 22 AWG wire circuit, expect 4-5 A derated at 85°C ambient; consult the MTA-100 application note for per-gauge derating curves.