The Reinz Water Pipe O-Ring - 407666700 is a small, circular rubber ring designed to fit around the water pipe of an engine. It is used as a seal to prevent leaks and maintain proper water flow within the engine. This O-ring is made by Reinz, a trusted manufacturer of automotive parts, and is specifically designed for use in engines. It is durable and reliable, providing a secure seal to ensure the efficient functioning of the engine. This product is essential for maintaining the proper temperature and performance of the engine, making it an important component for any vehicle.