Wireless headset uses 1.9GHz, DECT 6.0 technology, resulting in low interference, high audio quality and enhanced voice security. Multi-layered security system ensures secure conversations. Volume controls include receiver adjustment and transmit setting. PeakStopâ„¢ Protection guards against sudden volume spikes. Also features multi-unit conferencing capability (up to four callers) and support for electronic hook switch. Interchangeable earhook and headband wearing styles enable all-day comfort.