FCS II Finnen Retro Keel Twin - BlackLow aspect keel twin designed for fish shapes. Fast and loose with minimal drag. Overview Low aspect keel template designed for fish shapes with contemporary outlines and concaves. Lowest area keel in the FCS range. Feels fast and loose with minimal drag, and encourages a more progressive and radical approach to riding a fish. Board Types Designed to fit the FCS II Fin System. Recommended for all board types including fish, funboard, and twin fin