90308-ZV5-003 Nut (12Mm) - Overview. The 90308-ZV5-003 Nut (12Mm) is a precision-engineered fastening component designed for use within Honda marine engine systems. This self-locking nut plays a crucial role in securely fastening parts within the marine engine assembly, ensuring reliable operation and preservation of component alignment under demanding marine conditions. Manufactured to exact factory specifications, it guarantees seamless integration with existing parts, maintaining optimal perf