Shure BLX288/SM58-H9 Dual Handheld Wireless Microphone Mic System 512 to 542 MHz
H9: 512 to 542 MHz. The discrete MX153 sub-miniature earset mic and the CVL lavalier mic both provide exceptional clarity in spoken word applications. Shure BLX24/SM58 H9 Handheld Wireless Microphone Vocal System w/SM58 Mic.