Lock housing for 0.50 series
The 1903614-1 is a 6-position lock housing in TE's 0.50 series, designed to retain the mating connector pair on the harness.
Position count across the 0.50 series
The 1903614-1's 6-position lock housing sits between the 1981561-2 sealing plug (no position count) and the 2-1971778-3 locking plate (6 positions, Power Triple Lock series) — the 0.50 series lock housing is a dedicated accessory for the 0.50 connector family, not a cross-series part.