Yamaha Eric Miyashiro Model MK2-MK2 Sleeve modification done. Includes a "#7" sleeve. With the #7, I felt less resistance, making it easier to breathe and relax, and I felt a slight improvement in endurance. (This is just my personal impression.) The total cost, including the instrument itself, modification fees, and the sleeve, was over 20,000 yen. There are some minor scratches on the sleeve, but they do not affect performance. This is a used item, so please refrain from purchasing if you are sensitive to such things or have any concerns.