SRAM Red D1 Quarq Road Powermeter DUB 170 - 48-35 Yaw (BB not included)X Range gearing technology gives you more range and a smoother gear progression, so youre always in the right gear Power meter is fully integrated into the chainring set for lighter weight Power readings are accurate within + 1. 5% and arent affected by climate conditions during a ride Measures right and left leg power balance Improved front shifting performance for crisp and accurate front shifts Unique chainring shape results in a lighter weight,