Sennheiser  CC 510 Single-Sided Monaural Headset with Noise-Canceling Microphone Active Guard safeguards the user from the effects of an acoustic burst Easy disconnect Ultra noise-cancelling microphone Bottom cable not included Ultra noise canceling microphone Adjustable and pivotable microphone boom Interchangeable ear pad and side support Small, light-weight headset Individually adjustable microphone and headband