12-24mm autofocus zoom lens with f/4 maximum aperture for Nikon digital SLR cameras. 2 Extra-Low Dispersion (ED) glass elements and 3 aspherical lens elements for superior optics. D-type design provides precise distant information for flash and ambient light exposure. Rounded diaphragm makes out-of-focus elements appear natural; 11.8-inch close focus distance. Measures 3.2 inches in diameter and 3.5 inches long; weighs 1.07 pounds