http://t.co/livi3Bvs - <br /><br />Top Deal Review - Canon EF 17-40mm f 4L USM Ultra Wide Angle Zoom Lens for Canon SLR Cameras<br /><br />Technical Details<br />17-40mm ultra-wide-angle zoom lens with f/4 maximum aperture for Canon SLR cameras<br />3 aspherical lens elements and super UD glass element create superior optics in all conditions<br />Powerful ring-type ultra-sonic monitor (USM) produces fast and silent autofocusing<br />Focuses as close as 11 inches; supports screw-in 77mm filters or up to 3 gel filters<br />Weather-resistant construction; measures 3.3 inches in diameter; 1-year warranty
