Sunstar Works Aluminum Sprocket: We use only the highest quality aerospace grade 7075-T6 aluminum for high strength and light weight and computer designed weight reduction holes are included for even less weight. The Works Triplestar's exclusive tooth-and-valley design gives you 24% more chain contact area for a better transfer of power to the rear wheel and a larger area to distribute the chain impact stress resulting in a virtually indestructible sprocket. A HARD ANODIZED coating is applied to provide a super durable finish to an already great sprocket. For dirt applications only.