The 2-640456-2 is a 22-position, single-row, shrouded 1-wall header from the MTA-100 series. Square male pins (0.025" square typical for MTA-100) accept standard crimp terminals or IDC contacts from the same series; the tin-plated mating surface is rated for moderate cycle life, suited to equipment that sees periodic service rather than daily disconnect.
The insulation height of 0.305" (7.75 mm) sets the z-height above the PCB. All 22 positions are loaded; the header accepts a full complement of mating contacts, which is the standard for MTA-100 IDC receptacles and crimp housings.