Board-fit anchor: pitch and position count
The 1-647124-0: The 10 circuits are all loaded, so the BOM position count is exact: no empty slots to account for.
Retention and wiring environment
A friction lock on the header holds the mating receptacle in place — it resists vibration and cable pull without needing a secondary latch.
Contact finish and current handling
Tin-lead is a workhorse finish for moderate mating cycles — it doesn't offer the cycle life of gold, but for a connector that mates a few dozen times over its life, it's a cost-effective choice. The header is rated 600VAC — that's the maximum working voltage between adjacent pins or pin to ground. In a 24V or 120V control circuit, this gives generous headroom.