ITEM NAME:Universal Surf Single Center Fin Longboard Paddleboard Surfboard Fins 166mm img *{margin:0;padding:0;.Size 1 (W x H):Approx. The longboard surfboard fin seamlessly connects turns and allows surfers to move up and down the board. 1 Piece Longboard Fin. This versatile fin is designed for all conditions and combines drive,speed and response for modern longboarding.