Renthal rear chainwheels are manufactured to exteremly tight tolerences from a special material developed to withstand the rigours of Supercross, Motocross and Enduro 7075 T6 aluminium alloy rear chainwheels are 66% lighter than steel, yet incredibly durableAdvanced tooth profile, concentricity and accuracy of fit provide maximum power transfer and long-lifeRenthals combination of a very high strength base material and an exceptionally hardwearing surface result in significantly increased chainwheel lifeThis sprocket is designed for a stock 525 chain or conversion to 525 from larger sizesActual product may vary from web image.