Shure Blx14/CVL/630 Lavalier Wireless Microphone & Mini Headset Mic 512 - 572 Mhz UHF Band Frequency Up to 12 compatible systems per frequency band (region-dependent) One-touch QuickScan frequency selection quickly locates the best open frequency (in case of interference) Up to 300 feet (100m) transmission radius (line of sight) XLR and 1/4" output connectors