Rotor 110x5 Round Inner Chainring Rotor's 110x5 Round Inner Chainring features a CNC-machined 7075-T6 construction. This lightweight, stiff, and heat-treated process gives the chainring great durability. This 110 BCD chainring features steel shifting pins for improved shift precision and reliability. The Rotor 110x5 BCD chainring is compatible with 9, 10, and 11-speed groupsets. Features100% CNC-machined, 7075-T6 aluminum alloy construction Steel shifting pins for added precision and reliability Round, non-aero design Compatible with all 9, 10, and 11-speed groupsets Sizes: 43, 36, 38, 39, 41, 42, 44T | Rotor | 110X5 Round Inner Chainring 110X5, 39T | Aluminum