Feature:1. Made of aluminum alloy. Light weight, but it has a great strength and high performance.2. The front derailleur is removed, the load on the bike is reduced, the chain cannot be dropped, and reduce the annoy of chain dropping.3. The narrow wide design ensures that the chainring is more stable, effectiv ely protects frames from scratches, and can reduce friction and noise.4. The ergonomic round design can reduce the load on the legs or knees, ensuring more comfortable and smoother riding.5. The unique shape increases the contact area of the chain, improves the grip, and reduces the chain sag, making it easy to pass on uneven roads.Specification:Item Type: Bike ChainringMaterial: Aluminum AlloyProduct Size: (Allowable Error of Manual Measurement)Outer Diameter: Approx. 168mm / 6.6inAdjacent Aperture: Approx. 74mm / 2.9inDiagonal Aperture Approx. 104mm / 4.1inNumber of Teeth: 40T Package List:1 x Bike ChainringNote:Carefully observe the teeth of the chainring. The teeth are a little bit sharper, a little bit blunt, and a little shorter. This design is to make the chain easier to leave and adapt to the disc when shifting, and the shifting is smoother, and it is not a defective product.