Specialized Offset - This crank model is most suitable for Specialized Turbo systems using the ISIS mount including: Levo, Kenevo, Vado, Como, Turbo Levo e-bikes. Please note this model is not suitable for any Levo SL MTN E-Bikes using the Specialized SL 1.1 M30 motor.Key Features:Designed for maximum ground clearanceSelf-extracting system for easy fitting and removalAvailable in 155mm and 165mm lengthOptimised Q-factor for compatibility with most frame/motor combinationsArms available in Black, Blue, Red, Silver, Purple and OrangeProudly Designed, Tested and Manufactured in Barnoldswick, UKWeight: From 472gForged and CNC machined 7150 series aluminium alloy crank arms**Please Note**: Compatible with motor systems using an ISIS spline axle/crank arm interface only.Standard Offset - This crank model is most suitable for Bosch gen 2/4 systems and Yamaha PW-X systems (not compatible with Bosch gen 3 BNI spindle interface).Narrow Offset - This crank model is most suitable for Brose systems