Buy from Amazon.com : http://fave.co/1CcI1cs <br /><br />Sigma 180mm f/3.5 EX DG IF HSM APO Macro Lens for Canon SLR Cameras<br /><br />Product Description : <br />Floating Inner Focusing System <br />It is possible to use 14x or 2x Sigma Apo Tele Converters <br />Use of SLD Special Low Dispersion glass <br />Inner Focus