The CM-400 is a clip-type contact microphone using piezoelectric elements that transmits vibrations directly to the tuner by attaching the microphone to your instrument. The CM-400 enables even more accurate tuning than the microphone on the tuner itself, and allows the instrument to detect its own sound more reliably, especially when practicing with a large group or in other environments where the sound is easily affected by surrounding sounds. The cable, which excels in efficient sound transmission, is made of a material with a soft and flexible wire sheath. The slit shape of the joint between the clip and the cable reduces the load on the wire and makes it difficult for the cable to break. The output terminal for connection to the tuner body has a new mini-plug, which works well with the TM-70T and ensures stable tuning. The maximum width of the clip is 30mm, and the inner rubber part is designed to be attached to any instrument without leaving any mark or causing any damage. It can be attached easily and securely to a variety of instruments, such as the bells on wind instrument, the heads of bowed string instruments (such as a violin), guitar, bass and ukulele heads, and more.