It's a free-hanging (in-line) connector meant to mate with a matching SL-156 header on a board — a wire-to-board interconnect for power distribution or signal wiring where the 0.156" (3.96mm) pitch gives enough room for decent current per circuit without crowding the board.
The Sourcing Trap: Contacts Not Included
The listing spells it out: Contacts Not Included. This is the housing only — you crimp the female socket terminals separately and insert them into the cavities. If you're new to the SL-156 line, it's an easy miss: the BOM needs both the 1-770849-5 housing and the matching crimp terminals (TE part numbers 1-770190-0 or similar, depending on wire gauge).
The polarizing key prevents mis-mating.
It's a standard catalog part from the TE SL-156 family, still in regular production. No stock-holding claim from this listing — the RFQ is the step that locks in the supply.