For intensive use, including formal customer care centers, help desks, etc. Adjustable fit for all-day wear. Quick Disconnect feature provides easy disconnect/reconnect capabilities and compatibility with all Plantronics USB, desk phone audio processors, and direct connect cables. Flexible noise-canceling boom. Wideband audio up too 6,800 Hz. SoundGuard technology provides acoustic limiting for protection against sounds above 118 dBA. Sold by each. Black.