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 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)
