For Sale Sigma 10-20mm f/3.5 EX DC HSM Autofocus Zoom Lens For Canon Cameras. Had it for a year. Works perfectly. Clean glass. No issues. Comes with box.
Retails for $749 at Henrys.
http://www.henrys.com/24026-SIGMA-EX-10-20MM-F3-5-DC-HSM-CANON.aspx