I checked out the Free-sub link it it looks quite interesting. Itis non-english though and I think the language is in Turkish. Their products are also quit interesting as they seem to utilze a lot of tradional style designs and gear arrangements. Thanks so much for the link. Now if I could only find a dealer.
Yes, the language is indeed Turkish. I'm always on the lookout for basic gear using traditional designs and materials - as a snorkeller since the early 1960s I've always disliked plastic fins - which is how I chanced upon the Free-Sub fins during an online search.
As for finding a dealer, I only know of one online retailer,
Balikmarketim.com - Profesyonel ve Amatör Balýkçýnýn Alýþveriþ Sitesi | JET
and the company, of course, is Turkish as well. I've never tried the fins or used this online retailer, so I can't endorse either. They are only available in three sizes too, 40-41, 40-43, 44-45, the biggest, 45, approximating to US size 11. You may well end up following other contributors' advice because of the communication and distribution problems involved with acquiring this gear. Another alternative source of all-rubber stiff-bladed full-foot fins is the Japanese Gull Hard Mew, which I can recommend as I have a pair:
They're used by some underwater hockey players. Gull fins aren't widely available in western countries, but one Scubaboard contributor, who is based in Japan, is prepared to sell and ship them anywhere in the world:
http://www.scubaboard.com/forums/fins-masks-snorkels/242056-gull-diving-fins.html
As for Free-Sub, I can't help nurturing a sneaking admiration for small local diving equipment manufacturers that try to give, rather than tell, their customers what they want.