Sennheiser-s HMD 46-31-II series of very lightweight, extremely comfortable headsets are designed specifically for all air traffic control communication and C3 operators requiring excellent sound and long-term wearing comfort. A noise-canceling microphone delivers optimum speech clarity for reduced "call-back/read-back" events. The headset can be operated in two channel mode. Soft acoustic foam ear pads and patented two-piece automatic headband deliver first class comfort with a perfect, secure fit. A flip away headphone allows for single-sided listening and a reinforced flexible microphone boom allows for left or right sided use.