The 'high density' designation means the contact spacing is tighter than a standard DE-15 shell – 0.090-inch pitch versus the usual 0.108-inch – so you get more circuits in the same shell footprint.
This is a housing only – no contacts are included. You need to order the AMPLIMITE HDP-22 male crimp terminals (typically part number 1-66506-0 or equivalent) and a suitable insertion/extraction tool. The housing accepts signal-gauge wire; the contact cavity layout matches the standard HDP-22 pin arrangement. Free-hanging (in-line) mounting means no board footprint – the assembly terminates to a cable bundle.