The Zink FR E-Bike Crank Arms are built for Bosch, TQ, and Avinox motor systems, with a version specific to the Gen 4 Levo drive unit. A 150mm length keeps pedals higher off the ground through rock gardens and root-filled chutes, cutting down on strikes when the terrain gets technical. Every arm is CNC-machined from 7075 aluminum, precision-cut rather than cast, built to take repeated hard impacts without giving up strength. What Our Gearhead(R) Experts Are Saying:"I clipped a rock ledge hard enough to hear it and kept riding without a second thought. The shorter length and the machined aluminum are doing exactly what they're built for out there."