The Simpson Strong-Tie® RCKW is a heavy 171 mil (7 ga.) rigid connector that has been developed to resist overturning moment at the base of exterior kneewalls and parapets as well as interior partial-height walls or overhead ribbon window conditions. These connectors offer a unique small and large anchor-hole pattern that permits anchorage to both concrete and structural steel. The single-anchor RCKW has been redesigned to have all of the same features as the previous model but with an added two-anchor option that accommodates 1/2"- or 3/8"-diameter concrete anchors. If load requires more capacity, a stiffener, the RCKWS can be added. The RCKWS is a heavy 171 mil (7 ga.) stiffener that nests onto the RCKW clip. The screw holes and anchor holes in the stiffener line up with those in the RCKW clip, making fastener and anchor installation a snap. The RCKW clip and RCKWS stiffener are sold separately.