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.