Futures Fins are 1 of the 2 most prevalent surfboard fin systems in the world. Futures feature a single slotted box with one set screw at the top to lock your fin in place. The fin has a full length tab on the bottom where the contact with the board is maximized. The fin touches the box with it's full length. This eliminates any twisting or flexing where the fins meet the board, resulting in a very accurate ride.