The material used in the Grenaditte line was engineered and developed by Geoffrey Guo and only available from Guo Musical Instrument Company. Simply put, Grenaditte is an advanced composite material that is very dense but extremely light weight. The tone from a Grenaditte flute can be described as 30% wood, 30% metal, and 40% Guo. The Grenaditte line truly has a sound of its own. This is Grenaditte. This is the FUTURE.