Diatonic Deep Bass Metallophones are the finest instruments crafted by SONOR. Built entirely in the company s German factory only the finest materials and techniques are used 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. Because these metallophones are made with the best bar materal available they produce a consistent and long-sustaining sound.