These chainrings are fully CNC machined from high quality 7075-T6 aluminum and held to tight tolerances, producing a ROUND chainring. You know how much you hate tight/loose spots in your chain, right? This is the first step to eliminating that. These are also one of the lightest chainrings on the market weighing in at 31g for a 32t 104bcd. The lightening pockets are fully radiused resulting in a light AND strong ring. They are fully reversible and symmetric so when one side wears out, just flip it over and you're good to go! The pockets are also on both sides. All aluminum chainrings come anodized in your choice colors.