Board footprint and mated height
The BM02B-NSHSS-TBT(LF)(SN): Mated stack height is 7.8 mm, which means the header plus the mating receptacle sit low enough for most compact enclosures.
Current and environment
The BM03B-NSHSS-TBT and BM04B-NSHSS-TBT are identical in pitch (1.00 mm), current rating (1 A), voltage (50 V), stack height (7.8 mm), and material. If your BOM calls for 2 positions, this is the correct part; the 3- or 4-position versions are not pin-compatible drop-ins because the footprint length changes.