Pitch Instrument Tombo Gakki Seisakusho (Tombo Musical Instrument Manufacturing) Pitch Pipe Diameter: Approximately 72mm [How to Use the Pitch Pipe] While sounding the pitch pipe, turn the tuning peg of the string you want to tune until the two sounds match. This item was used by a relative for tuning a shamisen and has been stored for a long time. All the holes produce sound. When listing this item, I wiped it with alcohol wipes, but please understand that there may be dirt and scratches due to aging and use.