High-quality Trek Powerfly / Bosch crank set 175mm with ISIS mount with protection The extremely high-quality and stiff Bosch crank with ISIS mount of Trek with chain protection ring was developed especially for the use of the middle engine. The high-quality chain protection ring is mounted directly on the crank and protects against a jumping chain and injuries. Trek Crank Set Ride + Bosch 2 With guard 175mm Features  Original Features of the Trek Crankset: Compatible with Bosch Active and Active Line Plus drives, performance and performance CX ISIS standard 175 mm in length High quality aluminum with chain protection ring