The American Funds Mortgage Fund - Class R-5E (RMAHX) is a mutual fund that primarily invests in mortgage-backed securities issued or guaranteed by government agencies such as Fannie Mae and Freddie Mac. This fund aims to provide investors with a steady stream of income through the interest payments on these securities. It also seeks to maintain a stable net asset value (NAV) by investing in high-quality, low-risk securities. The Class R-5E shares are designed for retirement plans and have a lower expense ratio compared to other share classes, making it an attractive option for long-term investors.