Material: [carrier] aluminum, [rotor] steel Attachment Type: 6-Bolt Compatibility: metal, resin pads Diameter: 160, 180, 203mm Includes: 6 bolts, 3 rotor bolt washers When we're riding long gravel roads with punchy ups and downs we're relying on our stopping power. And, we're counting on that even more when the weather turns and the rain sets in. The SM-RT76 Rotor delivers consistent stopping power in all conditions so we can ride easy. It's compatible with metal and resin pads, and its aluminum construction drops grams and dumps heat.