https://purengom.com/2010/01/08/%eb%8b%b9%ec%8b%a0%ec%9d%98-%ec%8a%88%ec%96%b4-%ec%9d%b4%ec%96%b4%ed%8f%b0%ec%9d%84-%ed%95%b8%ec%a6%88%ed%94%84%eb%a6%ac%eb%a1%9c-shure-music-phone-adapter-mpa-3c/