The TE Connectivity 2-178128-3 is a 3-position receptacle housing from the Dynamic D-3200 series, built for wire-to-board or inline crimp connections on a 5.08mm pitch. The polarizing key on the housing prevents a mis-oriented plug from seating — a practical safeguard when the harness gets serviced in the field.
The listing note on this housing is clear: contacts are not included. The housing uses a crimp termination method, so the wire-to-terminal connection is made with a standard crimp tool, then the terminal locks into the housing. If you're filling a BOM line for this housing, add a line item for the terminals or the harness builder will have an empty shell and no way to populate it.
Mating Half — What Plugs Into This Receptacle
The polarizing key on the housing aligns with the corresponding slot on the plug header, so the two halves only go together one way. If you're building a cable-to-board interconnect, the plug header is the board-mount side; this housing is the wire harness side.