90R55: Nominal displacement is 55 cubic centimeters per revolution (cm³/rev).
90R75: Nominal displacement is 75 cm³/rev.
90R100: Nominal displacement is 100 cm³/rev.
90R130: Nominal displacement is 130 cm³/rev.
90L55: Nominal displacement is 55 cm³/rev.
90L75: Nominal displacement is 75 cm³/rev.
90L100: Nominal displacement is 100 cm³/rev.