Sinn watch ezm 10 testaf rubber the ezm 10 testaf was the first watch worldwide that has been tested and certified to the technical standard for pilots watches testaf by the aachen university of applied sciences this guarantees that the ezm 10 testaf meets all time measurement requirements during flights operated under visual flight rules vfr and instrument flight rules ifr and that it is suitable for professional use as a pilots watch this is attested to by a certificate and the test