Your chainring is one of the most important parts of your drivetrain. If it is not perfectly round, you will have tight spots and your drivetrain will bind, if it is not perfectly straight, you will throw a chain and go over the bars. The Supercross Pro Alloy Sprocket is CNC'd for 6061 T-6 aluminum, and then anodized with a splash of color. We found a box of these in the warehouse making room for 2013 product, and are blowing these out for 50% off retail price! Once these are gone, they are gone for good.