The Shure Model SM12A Professional Head-Worn Microphone and earphone is a low-impedance, unidirectional, dynamic microphone with an integral earphone assembly. Designed for sports and news announcing, interviewing and intercommunication systems, and for special events remote broadcasting, the SM12A offers convenient, hands-free operation without user fatigue. Drummers, keyboard artists and other musicians who need a vocal microphone -- one that will not pick up unwanted sounds -- will find the SM12A's smooth, natural voice frequency response and noise cancellation ideal for their applications. A close-talking unit, the SM12A may be used under noisy conditions without loss or masking of voice signals. The SM12A has two plugs on the end of the cable. 1/4" phone for the earphone and balanced XLR for the microphone.