Contact Microphone. The CM-200 Clip-On Contact Microphone with 1/4" Jack from Korg can be attached to any surface that vibrates and generates pitch. Common applications include the bell of a brass or woodwind instrument, the bridge of a string instrument, or a guitar top. The microphone captures the vibrations and sends them to your tuner. The CM-200 Contact Microphone is helpful if the mic built into your tuner might have difficulty detecting the sound of your instrument, such as when you're practicing with a large acoustic group. The CM-200 is comes with a cable that helps transmit sound efficiently, and is flexible. The connection between the mic and cable is durable, reducing the possibility of breakage. The clip opens up wide, providing sufficient space to attach to your instrument. The rubber inside the clip has been intelligently designed to provide a secure fit for attachment.