Features: 1.The crankset chainring is made of strong aluminum alloy to ensure they are resistant to wear and deformation. 2.With ergonomic design, stamping is used to generate more traction to reduce the load on the legs or knees and ensure a smooth ride. 3.The unique teeth design increases the contact area of ??the chain, prevents the chain from sagging, and allows you to easily pass on bumpy roads. 4.The narrow and wide teeth design of the chainring ensures that the chain is fixed, protects the frame from scratches, and reduces friction and noise. 5.Crankset chainring can be used without front derailleur, which greatly reduces the load on the bike and reduces the trouble of chain dropping. Item Type: 104BCD Crankset Chainring Material: Aluminum Alloy Outer Diameter: Approx.176mm/3.9in Adjacent Aperture Distance: Approx.74mm/2.9in Diagonal Aperture Distance: Approx.104mm/4.1in Teeth Number: 42T 1 x Chainring