The Sigma TC-1401 1.4× Teleconverter offers the extra zoom required for taking long-distant shots. This teleconverter can be used with Sigma SA-mount lenses. It provides full electronic functionality between the lens and camera, thus allowing your use the autofocus and autoexposure mode. The teleconverter comes with 7 elements in 5 groups. Thanks to the single Special Low Dispersion element, chromatic aberrations are reduced to ensure quality. The teleconverter offers a 1.4-times zoomed view of the lens' actual focal length while limiting the light loss to 1 stop. The teleconverter construction is splash- and dust-proof.