JS Industries Hydroglass Quad Trailer Fin

A quad trailer fin is designed to be used as the fifth fin in a five-plug surfboard setup. It adds stability and control to your quad configuration, helping you maintain speed and drive through turns without sacrificing the loose, fast feel of a quad.

These fins are compatible with both FCS II and Futures fin systems, provided your board has a five-plug setup. They are designed to fit into the center rear box of a quad configuration.

The 50/50 foil is symmetrical, which provides balanced water flow on both sides of the fin. This creates a stable, predictable feel that helps with control and responsiveness, especially when you need to hold a line through a turn.

This construction uses 34 layers of glass to create a stiff, consistent flex pattern. It offers a more traditional, solid feel underfoot compared to lighter composite materials, which helps with smooth rail-to-rail transitions.

Choose the template size that corresponds to your weight and the size of your primary quad fins. If you are a lighter surfer or ride smaller fins, the Small/Medium template is appropriate; if you are heavier or ride larger fins, the Medium/Large template will provide the necessary hold.