The 2X Teleconverter doubles the focal length of Canon EF lenses, with 4 groups, 7 optics, and 4x exposure enlargement (equivalent to 2 stops). Only compatible with select Canon EF lenses and supports autofocus. Offers excellent image quality and fast focus speed.Product InformationMount typeCanon EF-Mount lensMagnification2 timesDepth of Field Half of the original lensMin stacking focal length Equal to the original lensConstitution of the lens7 glasses, 4 groupFocus modeAutofocusLens CoatingMulti-coatedExposure factorApprox. 4 times (equal to 2 aperture )Diameter and length Approx. 68×51mmWeight Approx 154g