Canon EF-S 17-55mm f/2.8 IS USM Lens for Canon DSLR Cameras 17-55mm wide-angle zoom lens with f/2.8 maximum aperture for Canon DSLR cameras AD and aspherical elements deliver impressive image quality through entire zoom range, Closest focusing distance : 1.15 feet Image Stabilizer lens groups shift to compensate for image shake even in dim lighting Large circular aperture produces shallow depth of field; ring-type ultra-sonic monitor (USM) Measures 3.3 inches in diameter and 4.4 inches long; weighs 22.8 ounces; 1-year warranty