Canon EF 17-40mm f/4L USMSoodus

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