1/9
2.2 size = 2.125 inches (54 mm)
2.4 size = 2.25 inches (57.2 mm)
2.6 size = 2.375 inches (60.3 mm)
2.8 size = 2.5 inches (63.5 mm)
2.10 size = 2.625 inches (66.7 mm)