90210-438-000 Nut (10mm) - Overview. The 90210-438-000 Nut (10mm) is a crucial fastening component designed to support Honda marine engine systems. This nut plays a vital role in securing assemblies and maintaining the integrity and reliability of your marine equipment. Precision engineered to original equipment manufacturer (OEM) specifications, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. OEM 10mm flange cap nut designed sp