What are "Powerbox Forward" and "NUUS" fins? Scroll down. Our latest Freewave fin draws on a straighter leading edge to boost planing, and a squared tip to reduce drag. A thinner profile improves flex to improve control. Increased tip rake in the 21/23/25 cm sizes enhances maneuverability, while a more upright rake profile in the larger sizes prioritizes early planing, and upwind ability for larger freewave and freeride boards. G-10 construction.