Mike,
The smaller fin that you have may be a sinking model that was discontinued. If the small one has only one stomach hook hanger you have a rare redfin. The large 7 inch size also came as a sinking model - we used to call them red dots because the sinkers had a painted dot on the tail. Always thought our loaded fins fished better than the sinking models except for the small size - that plug was GOOD. Fish it but if you loose it let me know so I can scour the shore where you lost it
DZ