The 1-1445052-0: That pitch is standard for the Micro MATE-N-LOK series and gives you room to route a trace between pads on a 2-layer board without necking down.
Surface-Mount Assembly and Board Lock
This is a surface-mount header with board lock features. The pick-and-place cap allows automated placement — no hand-loading on the line.
Tin-lead is a legacy plating — it works for moderate mating cycles (50–100 typical) but is more prone to fretting corrosion than gold in high-vibration or low-voltage circuits. The voltage rating is 250 V, typical for signal and low-power circuits in this series.