 "Canon EF wide-angle lens - 20 mm" " Canon mm 2509A003 Camera & Camcorder Lenses CDW.com
"This ultra-wide-angle lens is ideal for serious applications. It is easy to hold and carry at 14.3 oz. (405g). It features floating rear focusing system. Sharp images are obtained at all subject distances." 
 "Canon EF 17-40mm f/4L USM"@en " Canon USM L series wide-angle zoom lens for EOS SLR cameras at Crutchfield.com "@en
"L series wide-angle zoom lens for Canon EOS SLR cameras"@en 
 General Brand Compatibility Canon Image Stabilization No Focal Length 17-40mm Maximum Aperture f/4 Weight 16.8 ounces Parts Warranty 1 Year Labor Warranty 1 Year