90016-ZA5-000 Nut, Special (5Mm) - Overview. The 90016-ZA5-000 Nut, Special (5Mm) is a specially designed component used within the Honda marine rigging and accessory systems. Its role is critical in securing various assemblies, ensuring clutch on precision and reliability in marine engine operations. Manufactured to exact OEM specifications, this nut guarantees seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Special 5mm nut designed for p