The 1-647123-0: It is fully shrouded (4-wall) with a friction lock, which means the mating receptacle is guided into alignment and held by a detent — no secondary latch, but enough retention for moderate vibration environments inside an enclosure.
Obsolete — Sourcing Reality and Lifecycle Status
The 1-647123-0 is officially obsolete per TE Connectivity's lifecycle record. There is no listed successor or cross-reference from the manufacturer — a board spin or an alternative series may be required.