Teleconverters designed exclusively for L-Mount lensesThe Sigma Tele Converter Tc-2011 are teleconverters designed exclusively for the use with Sigma L-Mount lenses. Mounted between a lens and a camera body, the Tc-2011 by 2x.The superior optical performance of the Sigma Contemporary, Art and Sports lines of lenses is the result of efforts to pursue the highest levels of image quality. The Sigma Tele Converter Tc-2011 upholds the image quality of the original lens to the utmost, while extending the focal length.In addition, the new teleconverters have a dust- and splash-proof construction comparable to that of the Sports line lenses, and can withstand harsh outdoor shooting environments when combined with a dust- and splash-proof camera body and lens.