When a mandolin is played in a rather large hall,or accompanied with other instruments, it won't be in tune with the instruments played at a high volume like the piano. So, here the director created a special mandolin devised to produce a richer volume and excellent timbre. Only by playing this mandolin, you will recognize its excellence. This instrument will be produced after you have made your order. Therefore, please allow plenty of time and forgive the high price. It is called a double-bottom mandolin in the mandolin community.