FCS II to FCS1 Fin Box Adapter river-surfing This fin sits right in

This fin sits right in the sweet spot — balanced enough for everyday training

cushioned contact point that prevents scratches

Capacity: 3 boards

🔒 Patented Hidden Mounting System

FCS II to FCS1 Fin Box Adapter river-surfing This fin sits right inConvert any FCS II surfboard into a standard FCS1 (Double Tab) setup. The Eisbach Riders FCS II Fin Box Adapter allows you to use traditional FCS1 fins in surfboards equipped with the newer FCS II fin system. Simply insert the adapter into the fin box and lock your FCS1 fins in place using standard fin screws. Perfect for surfers who want to keep using their existing fin quiver, test different fin templates, or replace broken fins without buying a