True Ames Greenough 4-A Longboard Fin - 10"/SandbarThere is a reason this is the most iconic, functional and versatile single fin available it works on just about anything! The Greenough 4 A has been our bread and butter for close to 40 years now, and is still the most popular single fin design there is. A truly well balanced fin the full base coupled with the tapering, moderately flexible tip provides a solid amount of drive off the bottom, and an acute responsiveness through arcing turns. Designed