FCS Lost MB Split Keel Quad

The split keel design is engineered to give you the drive and speed typically associated with a keel fin, but with the added maneuverability of a quad setup. It allows you to hold a line through turns without sacrificing the ability to pivot quickly in the pocket.

These fins use the FCS II system, which is designed for tool-less installation. They are compatible with any surfboard equipped with FCS II fin boxes, but they will not fit into older FCS dual-tab boxes that require screws.

Performance Glass is stiffer and more consistent than molded plastic or composite fins. This rigidity provides a very predictable flex pattern, which translates to more drive and responsiveness when you are pushing hard through turns.

Because of the stiff Performance Glass and the drive-focused design, these fins excel in clean, down-the-line waves where you want to generate speed. They are versatile enough for most conditions, but they really shine when you need to maintain momentum through sections.

While they are optimized for performance shortboards, you can certainly experiment with them on other shapes like fish or hybrid boards. Just keep in mind that the quad configuration and stiff flex pattern are designed to reward aggressive, high-performance surfing.