The 77313-124-70LF: It is designed for board-to-board or cable-to-board interconnects where you need a high pin count in a standard 0.100" pitch footprint.
Pitch, Pinout, and Board Footprint
The through-hole termination with a 0.114" (2.90 mm) post length gives a solid solder joint for manual or wave-solder assembly. Overall contact length is 0.480" (12.19 mm), with the mating pin extending 0.266" (6.75 mm) above the insulation body. This gives enough reach for mating with standard socket strips or crimp housings without bottoming out.
Plating and Contact Reliability
The mating contact finish is gold or GXT — a palladium-nickel alloy — with a thickness of 30.0 µinch (0.76 µm). The solder tails are tin-plated (78.7 µinch / 2.00 µm) for good solderability.