Great Planes OS 20-40FP/25-46FX&SF Adapter Kit FEATURES: Adapter kit for aluminum spinners This steel adapter kit tightens the backplate & propeller onto the engine, then using a single bolt-on des INCLUDES: (1) Propeller Nut (1) Propeller Washer (1) Aluminum Backplate Bushing REQUIRES: 12mm Wrench To Tighten Propeller Nut Aluminum Spinner w/Center Mounting Hole 10-32 Bolt