The 5-146256-9: It carries 18 male pin contacts in a dual-row, 0.100" (2.54mm) pitch layout, with all positions loaded.
At 3A per contact, the total current across all 18 positions is 54A, but the practical limit depends on the number of simultaneously active pins and the ambient temperature — derating applies above 25°C per the AMPMODU Mod II application note.
Comparing with peer 1376779-2
The closest functional alternative is TE's 1376779-2, which shares the same 18-position, dual-row, 0.100" pitch, through-hole, unshrouded header format and 3A current rating. The key difference is the mating gold thickness: 1376779-2 uses 8.00µin gold versus 15.0µin on the 5-146256-9, which reduces the mating cycle life. The 1376779-2 also ships in box packaging rather than bulk.