The water drain plug ring for Citroën 11CV, 15CV, and HY is an essential small component designed to prevent leaks in the cooling system. This ring provides an effective seal where the drain plug and cooling system meet. With proper maintenance and replacement per specifications, this ring minimizes the risk of overheating by preventing unwanted coolant leaks. Specifically manufactured for classic Citroën models, it ensures the reliability and functionality of the vehicles, supporting the preservation of their historical value. An indispensable part for owners seeking authenticity and performance in their vintage cars.