Dual Sprockets have been engineered with you in mind, to outlast standard aluminum sprockets and be much lighter than steel sprockets. The Outer ring on these sprockets is made from heavy-duty steel while the inner ring is made from 7075-T6 aluminum that has been anodized in a variety of different color options. Dual sprockets feature self-cleaning mud grooves between each tooth to prevent dirt build-up so you can spend less time cleaning and more time riding.