The new teleconverters have been exclusively developed for the new lens product lines. Attaching the TC-1401 teleconverter between a telephoto lens and a camera increases the focal length by 1.4 times, while attaching the TC-2001 model increases it by 2 times. Both models feature SLD (Special Low Dispersion) glass elements that provide excellent image distortion correction. It is remarkable that high-quality glass materials are used for lens accessories. However, since Sigma aims for the best possible image quality, this development is a logical step to meet the new "SGV" standards. The converters are dust and splash resistant, making them a durable construction for professional use. They are compact and lightweight, offering an easy way to extend the focal length range.