This circulating water pump is a replacement for inboard engines in boats. It is designed to keep the water flowing through the cooling system to prevent overheating and ensure the engine runs smoothly. Made from high-quality materials, it is durable and reliable for long-term use. The pump is compatible with a range of boats and is easy to install, providing a cost-effective solution to keeping your boat's engine in top condition. With its efficient performance and low maintenance requirements, this circulating water pump is a must-have for any boat owner. Note: Replacement for Mercruiser, 1968-1998 OMC, Stern Drive, Chrysler and Indmar, Inboard Engines, Replacement Numbers 8MO113734, 8503991, 18-3599-2, 17437.45