FCS II Performer Performance Core Single Surfboard Fin - Large/BlueThe Performer Single fin features the FCS II toolless LB fin base on a standard Performer thruster fin. This fin allows the user to convert any board with a fin box into a thruster set up. Available in M, L and XL thruster sizes, the Performer template is regarded as a versatile, all round fin for all conditions. It can be paired with Performer side fins, or any other side fins to convert a 2 + 1 into a thruster, essentially making the board looser