What this 4-pin ATX header is built for
The 2-1775099-0: This is a 4-position, dual-row pin header from TE's ATX series, on a 0.165" (4.20 mm) pitch. The four-wall shrouding and locking ramp make it a wire-to-board connector meant for environments where the cable needs to stay put — think power supplies, white goods, or industrial control panels where vibration or accidental tug could unseat a plain header.
That, plus the pair of board lock features on the through-hole tails, means the header resists being pried off the PCB during cable strain or rework. The board locks also hold the part flat during wave solder, preventing skew. The insulation is ivory-colored polyamide (PA9T, Nylon 9T) rated UL94 V-0. PA9T handles higher reflow temperatures than standard nylon, which matters if this board sees lead-free soldering profiles.