A removable daughter card assembly including a circuit board having a leading edge. The daughter card assembly also includes connector modules that are configured to be mounted to the circuit board proximate to the leading edge. The connector modules face in an insertion direction for engaging corresponding mating connectors when advanced in the insertion direction. The card assembly also includes an elongated stiffener that is configured to be mounted to the circuit board. The stiffener includes a plurality of support walls and a bridge member that couples to each one of the support walls. The support walls are secured to the circuit board. The bridge member extends substantially parallel to and proximate to the leading edge and is dimensioned to prevent bowing along the leading edge. At least two of the support walls comprise alignment features that are configured to engage corresponding guide features of a communication system.