91251-ZW6-003 Seal (11X21X8) - Overview. The 91251-ZW6-003 Seal (11x21x8) is a precision-engineered water seal designed specifically for Honda marine engine systems. This essential component plays a crucial role in preventing water, contaminants, and fluid leaks, thus ensuring the reliable operation of your marine equipment. Manufactured to match factory specifications, this OEM seal maintains optimal sealing performance compatible with Honda's engineering standards, allowing for seamless integr