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 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 exceptional that high-quality glass materials are used for lens accessories. However, since Sigma aims for the best possible image quality, this development aligns with meeting 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.