About Shimano SLX SM-RT66 180mm 6 Bolt Disc Brake RotorShimano's SM-RT66 6-bolt disc brake rotors deliver consistent stopping power in all riding conditions. The disc brake rotor's reliable anti-loosen plate construction makes for quick and secure installation. FeaturesLarger disc brake rotor option provides consistent brake performance with more power Easy to install anti-loosen plates help secure disc brake rotor bolts in place Resin/Metal pad compatible SpecificationsModel No: SM-RT66 Series: SLX M670 Series Remarks: With anti loosen tightening plate 6-bolt (P.C.D. 44 mm): Yes Outside Diameter: 180mm Pad Material Compatibility: Metal, Resin Pad Lining Shape Compatibility: Narrow About ShimanoShimano is a Japanese multinational manufacturer founded in 1921 by Shozaburo Shimano. They are well known as the largest bicycle component manufacturer in the world with their main manufacturing plants in Kunshan, China; Malaysia; and Singapore. Along with cycling components they also produce fishing tackle, and rowing equipment.