Captain Fin Co. Jeff McCallum Keel Acid

Yes, the Jeff McCallum Keel Acid fins are specifically designed for the Futures fin system. They will drop directly into any standard Futures fin box.

The flat foil provides a more responsive, predictable feel compared to a double foil. It helps the board initiate turns quickly and offers a classic, reliable sensation that many surfers prefer for retro twin-fin setups.

These are designed specifically for retro twin-fin fish boards. While you could technically install them on other boards, their large surface area and rake are optimized for the drive and drawn-out lines characteristic of fish shapes, not high-performance shortboards.

Fiberglass is a stiffer, more durable material compared to plastic or composite alternatives. This added stiffness provides more stability and drive during powerful bottom turns, which is essential for the speed-focused nature of a keel fin.

Not really. These are large keel fins built for speed, drive, and smooth, drawn-out carves. If you are looking for tight, vertical snaps, you would be better served by a smaller, more upright fin template.