The 2-1871935-1: This is a 22-position, dual-row header on 3.50 mm pitch, with a row spacing of 3.30 mm. The 4 A per-contact rating at 150 V is typical for this pitch class; the current ceiling is set by the contact cross-section and the housing material's thermal limit.
Shrouded 4-wall with detent lock and board lock
The full 4-wall shroud prevents the mating plug from being inserted off-angle, which protects the contact beams from stubbing. The insulation height of 11.80 mm gives clearance for the mating housing's latch and wire exit.
Peer comparison — 1-1871673-2
The difference is position count: 2-1871935-1 carries 22 circuits; 1-1871673-2 carries 16 circuits. If your BOM calls for 22 positions, the 16-position part will not fit without a board layout change.