90508-ZVD-000 Washer Plain (10mm) - Overview. The 90508-ZVD-000 Washer Plain (10mm) is a fundamental component in Honda marine engine systems. It serves as a simple yet critical hardware element designed to distribute load and prevent damage to mounting surfaces. Essential in various applications, this plain washer supports the rigging and accessory systems, ensuring dependable performance and longevity of your marine equipment. Crafted to factory specifications, it ensures seamless integration