Sigma APO Teleconverter 2x EX DG for Canon Digital SLR Cameras Black

APO Teleconverter 2x EX DG for Canon Digital SLR Cameras APO Teleconverter 2x EX DG
The dedicated 2x APO Teleconverter features a 6 element/5 group optical design, and it is specifically designed for use with longer telephoto and telezoom lenses.
The high performance optical characteristics of these teleconverters maintain the optical performance of the compatible lenses with which they can be used.
Using 10-pin electrical interfaces, there is no loss of autofocusing speed when these teleconverters are used with compatible H.S.M. type lenses for Canon, Sigma, and now current Nikon AF cameras (except N60/F60 models). They are ideally suited for use with the 70-200mm F2.8 APO EX HSM zoom lens; providing normal exposure and autofocus function, while maintaining its high optical performance.