The 77311-118-27LF: The 0.230" (5.84mm) mating pin length gives enough reach for standard box headers or shrouded receptacles.
No keying or polarization; the pinout is defined by the board layout. Termination is solder to through-hole. The 0.120" post length suits single- or double-sided boards; the square pin profile provides good solder-wetting area.
