The MFS Emerging Markets Debt Fund Class B (MEDBX) is a mutual fund that primarily invests in debt securities issued by emerging market countries. This fund aims to provide investors with exposure to the potential growth and diversification opportunities of emerging markets while also managing risk through a portfolio of fixed income securities. With a focus on debt securities, this fund may offer a higher yield potential compared to traditional equity funds. The Class B shares of this fund may have a lower initial investment requirement and higher expense ratio compared to other share classes. Overall, the MEDBX mutual fund offers investors the opportunity to participate in the growth of emerging markets while also providing potential income through fixed income investments.