The Nissens Engine Coolant Expansion Tank - 996270 is a replacement part for a vehicle's cooling system. It is designed to hold and regulate the amount of coolant in the system, allowing for proper engine temperature control. This expansion tank is made from high-quality materials and is built to withstand the demands of daily driving. It is specifically designed to fit the specifications of the 996270 model and is a reliable and durable option for maintaining a properly functioning cooling system in a vehicle.