Canon EF 16-35mm f/2.8L ll USM Zoom Lens for Canon EF Cameras 16-35mm ultra-wide-angle zoom lens with f/2.8 maximum aperture 3 high-precision aspherical lens elements produce superior image quality, Closest focusing distance: 0.92 feet Circular aperture produces natural background blur at wider apertures, Ring-type USM for fast and quiet autofocusing; internal focusing Measures 3.5 inches in diameter and 4.4 inches long; 1-year warranty