925 silver: Most commonly used precious metal in flute construction - also known as Sterling Silver. This is an alloy of 925 parts of pure silver and 75 parts of copper. The copper is necessary to give silver its hardness so that we can use it in objects. Silver Eloy flutes have a wall thickness of 0.35mm, resulting in a warm and bright sound that carries well. The head joints have a slightly thicker wall: 0.38mm. This gives a balanced sound without loss of quality through all registers of the flute.