FCS II Reactor PC Tri Fin SetDesigned for speed and tight turns Designed for speed and tight turns, with added tail release. Upright template allows for tighter, more acute directional changes. Smaller centre fin for increased pivot and tail release. Ideal for surfers who like to perform fast, progressive turns. Board Types Designed to fit the FCS II Fin System. Recommended for performance shortboards with moderate to low rocker. Fin Family Reactor: Find Speed. Speed, tight turns