Sierra's 18-2587 Power Steering Cooler is designed for Mercruiser. It features a 6" tube bundle and 8" overall length. The water inlet and water outlet is 1-1/4" in size. Shipped bare metal, ready for primer and factory paint finish. The package includes one power steering cooler per package. It is interchangeable with Mercruiser Stern Drive 99356A2. Each Sierra product meets or exceeds the original equipment part it replaces.