The Timeless Resonance of Ancient Wood and Bamboo Old wood knots and bamboo create a harmonious sound that transcends time. Old pine knots are a rare material harvested from the knot sections of pine trees that have endured years of wind and snow. Old bamboo is bamboo that has aged over many years, its fibers tightened, producing a light yet strong resonance. This two-layered structure creates a bridge that balances power and delicacy. Size: 15mm x 12mm x 9mm There may be slight individual differences due to handcrafting.