What is the TE 66103-1?
This is the pin half; it mates with a socket contact in the same series, so you need the matching socket to complete the circuit.
What housings are compatible?
As a Multimate III+ pin contact, the 66103-1 fits into any TE housing that accepts that series' stamped pin — typically the CPC (Circular Plastic Connector) and similar rectangular industrial housings. The 20-24 AWG wire range and crimp barrel size are standard for signal-level circuits in those housings. Confirm the housing cavity count and keying before committing the BOM line.