Material: Natural 5-year-old bamboo , N aturally d ried over 3 years . -Comes in 5 keys of C, D, E, F and G. If you purchase the entire set from the selection below, you get the Aluminum Case Free A basic model meant for aspiring students who wish to have a good tone for standard solo performances and ensemble musicians. Using properly dried bamboo, coupled with the decades of experience Lin Yin and her founder Dong Xue Hua has with making flutes for top level musicians.