The 5499345-6: The shrouded 4-wall body with keying slot and mounting flange keeps the cable assembly aligned and locked during mating, which matters when the harness gets plugged and unplugged repeatedly in a panel or chassis.
Pitch, current, and plating — what drives the fit
At 2.54mm pitch and 26 positions, the footprint spans roughly 1.3 inches across the rows. For a 26-wire cable carrying a mix of signals and low-power lines, this is well within the margin.
Latch lock and keying — vibration and mis-mate protection
The keying slot in the housing ensures the cable plug cannot be inserted upside down or into the wrong header position, which saves a debug session on the line. The mounting flange gives you a screw-down option to the board or panel for extra strain relief — useful when the cable is routed through a cable tie or conduit and the header sees pull force.