Position count across the Dubox single-row family
Within the Dubox single-row receptacle family, the 21-position 75915-421LF sits between the 20-position 75915-420LF and the 22-position 75915-422LF — the 0.100" pitch, tin plating, and through-hole termination are shared across the series, so the selection narrows to circuit count matching the board layout.