Originally popular as glass-ons in the 1960's, now "D” fins sometimes need to be put in fin boxes, so we have made 2 designs to pick from. The larger area on these fins allows for harder turning and easier nose riding. Try one on your log and take a trip to the past.
Both fins will just fit in the 10” standard fin box because we have made an overhang in the rear of the fin. You may have to take out your “fin box leg rope” but mostly we know D-fin riders do not use such newfangled attachments anyway.