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.) Including the instrument cost, modification fee, and sleeve cost, it probably cost over 20,000 yen. The sleeve has some minor scratches, 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.