Mac was kind enough to let me know of this question.
All Curtis Fins are provided with solid boxes. Adaptors are a joke as far as we
are concerned. They are not stiff enough to work with modern fin designs.
The only exception has been that occaisonally we use them on special order for
fins under 27 cm. This is not something we encourage.
We typically offer US/ES, Power, Tuttle, Trim, some deep Tuttle and F2 Thommen
in appropriate designs. Tiga, Meretex are available in some designs.
Fin Depths range up to 56cm. For further information you can check the website
Gorge Sport USA
Curtis Performance Fins, Orca Fins
Hood River, OR USA
ph/541 387 2649 fax/541 386 1715