Canon EF Extender 2x III

Improved anti-reflection materials inside the lens-barrel and a coating around the outer edges of the lens elements reduce flare. Construction is resistant to dust and water, helping to maintain images quality. A built in microprocessor provides accurate transfer of data from between the lens and camera delivering an improved performance in AF and metering. The Extender EF 2x III is compatible with most telephoto and telephoto zoom lenses within Canon's flagship professional L-series range, extending the focal length while only reducing the effective aperture of the lens by two stop.