Contact system and board fit
The 9-146280-0-21 is the 21-position member of TE's AMPMODU Mod II breakaway header line, a single-row unshrouded male pin header with 0.100" (2.54 mm) pitch. Gold-plated mating contacts rated 3 A per position, with tin-plated posts for solder termination through a 0.120" (3.05 mm) tail.
Breakaway sizing and routing
The unshrouded push-pull design and 0.230" (5.84 mm) mating contact length allow the header to be snapped to the required circuit count before assembly — the 21-position variant fits boards where the BOM calls for a full row of 21 circuits at 2.54 mm pitch.