The CWP-7's universal design has a rotating tip pressed into each end of the tool (0.445” and 0.642”) so it will remove both square taper and splined (ISIS Drive, Octalink) crank arms. It also fits BNI cranks on e-bikes. The CWP-7 is made for the 0.866” x 0.039” threading on common cranks. Small Rotating Foot: Compatible with systems that use an M8 x 1.0 threaded crankset including: Square Taper, SRAM PowerSpline cranks and BNI e-bike systems Large Rotating Foot: Compatible with systems that use an M12 x 1.0 or M15 x 1.0 threaded crank bolt including: Shimano Octalink, ISIS Drive and ISIS Overdrive systems NOTE: The CWP-7 is designed for cranks with M22 x 1.0 extractor threads. Crank arms found on some fitness equipment use non-standard extractor threads and are not compatible with Park Tool crank extractors. Consult your equipment manufacturer for tool recommendations.