Item Type:104BCDCrankset ChainringMaterial: Aluminum AlloyOuter Diameter: Approx.176mm/3.9inAdjacent Aperture Distance: Approx.74mm/2.9inDiagonal Aperture Distance: Approx.104mm/4.1inTeeth Number: 42T .wang-edit-text{ font-family:'Arial' important; } .wang-edit-text table { border-top: 1px solid 000; border-left: 1px solid 000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid 000; border-right: 1px solid 000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; } 1The crankset chainring is made of strong aluminum alloy to ensure they are resistant to wear and deformation. 2With ergonomic design, stamping is used to generate more traction to reduce the load on the legs or knees and ensure a smooth ride. 3The unique teeth design increases the contact area of the chain, prevents the chain from sagging, and allows you to easily pass on bumpy roads. 4The narrow and wide teeth design of the chainring ensures that the chain is fixed, protects the frame from scratches, and reduces friction and noise. 5Crankset chainring can be used without front derailleur, which greatly reduces the load on the bike and reduces the trouble of chain dropping.