A:crank 1pair+32Tchainring 1+BB 1. B:crank 1pair+34Tchainring 1+BB 1. C:crank 1pair+36Tchainring 1+BB 1. D:crank 1pair+38Tchainring 1+BB 1. Material: Crank 6061 T6 aluminum alloy/shaft 7075 T6 aluminum alloy.