How do I know which one is genuine on SM-RT66 rotors? One says made in China (SK) while other says Japan (RA). Both has different edges. Please confirm. Got china one from
SHIMANO SM-RT66 Disque de Frein pour Freins 6 Trous Argent Argent Diamètre 160 mm & Adaptador Freno Disco 180mm-SM-MA-F180 Post/Standard Noir Taille Unique : Amazon.fr: Sports et Loisirs