The Sierra 18-3006 Impeller is a high-quality replacement part designed for OMC 378891 engines with 30-33hp, 35hp, 1967-77, 40hp, 1971-1973. Manufactured by Sierra, a trusted brand in the boating industry, this impeller is specifically designed to provide efficient cooling systems for outboard engines. With durable materials and precise engineering, the Sierra 18-3006 Impeller ensures optimal performance and reliability for your boat's engine.