More on Amazon.com : http://www.amazon.com/gp/product/B000JSZ41S?tag=thefatkidin06-20 <br /> <br />Opteka High Definition 2X Telephoto Converter for Opteka 650-1300mm 500mm and 800mm SLR Lenses <br /> <br />Doubles your zoom on the Opteka 650-1300mm 500mm and 420-800mm Lenses <br />Works ONLY with compatible T-mount Lenses <br />High Definition Glass
