The 1761607-7: It is a through-hole, right-angle mount with a shrouded 4-wall housing and a latch lock/eject hook system for secure mating. The 1A per contact current rating and gold or gold-palladium mating finish make it suitable for signal-level applications in industrial control, telecom, and test equipment where repeated mating cycles are expected.
The 20 positions are fully loaded, so no blank positions to account for on the PCB layout.
Latch lock and vibration duty
This is a step up from a simple detent lock found on some lower-cost headers.