We offer the fins exclusively as a complete set because they were engineered to work in perfect harmony — exactly as Kai intended.While other brands rely on compromise designs that need to work across multiple setups (single, tri/thruster, quad), the TRI fin set is different. It’s a no‑compromise, high‑end solution created to meet — and exceed — the expectations of World Cup‑level riders. In fact, it’s an open secret that many of the sport’s top professionals have been relying on Kai’s custom fin designs for years. Now, that same elite performance is available to every rider.Shorter fins. Higher performance.One of the key indicators of their efficiency: our fins are 1–2 cm shorter than comparable tri/thruster sets. This is made possible through our exclusive AI_FIN CAD software, which creates a flawless, highly efficient profile transition in the critical tip area where the fin sweeps backward. The benefits?Radically improved maneuverabilityExcellent grip without any sticky feelingInstant, precise response in every turnPremium materials. Maximum perfection.The center fin is precision CNC‑milled from black G10, an ultra‑dense, prepreg‑laminated fiberglass block. G10 is the ideal choice for medium-size maneuver center fins.The side fins are injection molded using our exclusive CARBO_TECH material to ensure the necessary tip flex despite the short length.This is the level of quality and consistency that serious wave sailors expect.Choosing the right sizeSelect your TRI set according to the recommendations below. Oversized fins generate excessive tail lift, making your board feel sticky and harder to turn. The correct size ensures your board performs exactly as intended — loose, fast, and precise.