Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens for Canon SLR Cameras 17-40mm ultra-wide-angle zoom lens with f/4 maximum aperture for Canon SLR cameras.Diagonal angle of view 104 - 57 30' 3 aspherical lens elements and super UD glass element create superior optics in all conditions, Closest focusing distance : 0.9 feet Powerful ring-type ultra-sonic monitor (USM) produces fast and silent autofocusing, Focuses as close as 11 inches; supports screw-in 77mm filters or up to 3 gel filters Suitable for Wedding/Nature Photography, Weather-resistant construction; measures 3.3 inches in diameter; 1-year warranty Purchase this product between May 1, 2016 and July 30, 2016 and get 13 months of free damage protection from Canon. The product must be registered within 30 days of the purchase date to be eligible.