Greenough 8" 4A Single FinGreenough 4 A Single Fin Description The Greenough 4 A Single Fin is one of the most iconic, functional, and versatile single fins ever designed. Known for its balanced performance, it works exceptionally well across a wide variety of surfboard shapes and surfing styles. A staple in the True Ames lineup for over 40 years, the 4 A continues to be their best selling fin. Its timeless design delivers smooth flow, reliable control, and all around