Futures Alpha Reverse Twin Fin - Eastern Lines,ALPHA REVERSE 3/2 TWIN+1 Designed to surf your favorite twin board at full throttle. The “Reverse 3/2” refers to the twist in the foil, through the top third of the fin, that,Alpha Reverse 3/2 Twin+1 – Futures Fins US,Alpha Reverse 3/2 Twin+1 – Futures Fins US