At the bottom of the hand dish is a hole called the "Gu" in the edge of the inner roll, which is used for tuning the bass. All notes have excellent resonance vibration. Made of brass, edge is coated with protecting border.The item "14 Notes Hand Pan Handpan Drum 14 Inch Steel Tongues Brass C Manual Percussion" is in sale since Thursday, November 21, 2019. This item is in the category "Musical Instruments & Gear\Percussion\Folk & World Drums\Handpans". The seller is "nuflower2009" and is located in Shenzhen. This item can be shipped worldwide.