90303-ZVP-000 Hex (18Mm) Nut - Overview. The 90303-ZVP-000 Hex (18Mm) Nut is a critical hardware component supporting Honda marine engine rigging systems. Its primary role is to securely fasten parts within the mechanical assemblies, ensuring reliable operation under marine conditions. Designed for durability and precision, this nut ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Type: Hexagonal Nut (18mm) designed specifically for