Description: 【All in Integration】: Combines rudder, shaft bracket, and flexible shaft assembly into a single unit for simplified installation and improved operational convenience 【Precision CNC Machining】: RC boat rudder kit manufactured using high precision CNC technology to ensure exact dimensions, smooth operation, and reliable performance in model boating applications 【Aircraft Grade Aluminum】: Flexible drive shaft support constructed from premium aluminum alloy for superior strength,and long term durability in freshwater and marine environments 【4.0mm Shaft Compatibility】: Boat model flexible shaft kit designed for seamless integration with standard 4.0mm propulsion systems, offering broad compatibility across various model boat designs 【Double Hull Specialization】: Optimized for catamarans and cat boats, support bracket providing enhanced stability and maneuverability for demanding races or recreational use Specification: Material: Aluminum Alloy   Size Chart: 11cmx9.7cmx2.8cm/4.33inchx3.82inchx1.10inch Package Includes: 1x RC Boat Rudder Kit Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.