Canon EF 16-35mm f/2.8L USM Ultra Wide Angle Zoom Lens for Canon… The first EF wide-angle zoom to combine three Aspherical elements and Canon? S UD glass, the lens remains compact while providing superior image quality across its range. Constructed to pro standards, it? S also highly resistant to dust and moisture. A superb lens that covers nearly every professional wide-angle task. Outstanding optical performance comes from three Aspherical lens elements, and (for the first time ever in an EF wide- angle zoom lens) two Ultra-low Dispersion UD elements. Weather resistant construction, a rear gel filter holder, close-focusing to 11 inches (0.28m), and a circular diaphragm are among its many highlights. Micro UltraSonic Motor (USM). F/2.8 constant maximum aperture. Super Ultra-low Dispersion glass; inner focusing; aspherical lens; full-time manual focus. EF mount; ultra-wide zoom lens. Focal Length Description: 16-35 millimeters. Lens Type: Wide Angle. Compatible Mountings: Canon EF. Camera Lens Description: 12. Product Dimensions: 4.06 x 3.31 x 3.31 inches. Item Weight: 1.32 pounds. Item model number: 7261A002.