The 77313-818-12LF: The dual-row, 12-position arrangement occupies a 0.100" row spacing, so the overall width across the two rows is 0.100" plus the pin body width. That saves board space and gives the mating receptacle direct access, but it also means the header offers no keying or polarization against mis-mating.
Current Capacity and Contact Finish
At 3 A the temperature rise inside the housing stays within the UL94 V-0 thermoplastic limit. For signal-level loads (under 1 A) the margin is generous; for power distribution, derate if ambient exceeds 85°C. That thickness supports 200–500 mating cycles in typical board-to-board or cable applications. In a field-service connector that gets cycled quarterly, that is decades of reliable contact.