Forza Short tendon foot pockets.
Lightweight and made from soft rubber (TPR) with a shortened side tendon to give added protection to fins whilst allowing them to flex more than a standard tendon.

The size of foot pockets corresponds to the size of bare feet. Forza Size chart in pictures.
From Leaderfins: Please choose the next size if you intend to wear 3-5 mm socks. Example - your barefoot size is 43-44 => with 3-5 mm socks you should choose size 45-46.