Liberate your performance with the GLXD14/SM35 Wireless System. Using hand-picked components Shure have created a uniquely lightweight and comfortable headset microphone. Without compromising durability. Subject to the same extreme testing as any other Shure mic the SM35 simply out-lasts the competition. And it;s been fused with elegant GLX-D technology – for wireless freedom you can really trust. Setup is simple. Intelligent LINKFREQ technology finds the best frequency for your performance. And if competing signals are detected from nearby Wi-Fi and Bluetooth devices your receiver will automatically switch to a new clear frequency. Its totally seamless with zero interruption to the audio. Just fault free performance every night.