The Sonor Diatonic Soprano Metallophone is crafted wth the highest-quality bar material available. They produce a consistent and long-sustaining sound. Meisterklasse are the best instruments crafted by Sonor. Built entirely in the company s German factory only the finest materials and techniques are employed in creating these sonically and physically superior instruments. Meisterklasse metallophone bars consist of a special light alloy and are 1 cm thick with one hole at the top. They are precisely and harmonically fine-tuned to A-440 standard. C2-A3.