This Supertech black nitride exhaust valve is specified for Subaru EZ30 H6 first-generation engines and is sold as a single valve. The black nitride coating is noted in the source description as the finish, and the valve is intended for replacement or rebuilds of the EZ30 H6 valvetrain. It serves as a direct-fit service item for maintaining or refreshing exhaust valve components on supported engines.
Supertech Subaru EZ30 H6 (1st Gen) Black Nitride Exhaust Valve - Single