This is the Hot Racing CNC Turn Fin for the Traxxas SPARTAN BOAT FEATURES Increases performance and handling for SPARTAN BOATS Hot Racing high performance turn fin and mounting bracket will help your boat turn faster with more stability in both right and left turns. It will also provide better straightaway handling. Aluminum Construction Polished finish Easy to install light weight Adjustable INCLUDES (2) Turn fin (2) Turn Fin Mounting Bracket (2) 3mm Lock Nuts (2) 3mm x 12mm Screws REQUIREMENTS Installation with stock 4 x 12 staleness steel screw SPECIFICATIONS length: 79 mm width: 26 mm Thickness: 3 mm.