The Alcon Pro-System replacement rotor specified as 328 x 1.385 in x 50.5 mm is offered as a right-side rotor made to those dimensions. Sold as a direct-replacement rotor, it matches the listed diameter, thickness, and mounting to maintain correct pad contact and braking function where that specific 328-size right rotor is required.
Alcon Pro-System 328 x 1.385in x 50.5mm Rotor - Right