Canon EF 180mm f3.5L Macro USM AutoFocus Telephoto Lens for Canon SLR Cameras 180mm macro lens with f/3.5 maximum aperture for Canon SLR cameras 3 UD glass elements and internal floating system combine to minimize aberrations Advanced ultra-sonic monitor (USM) for high-speed, quiet autofocusing Focusing distance range of 1.57 feet to infinity; supports EF Extender 1.4x and 2x Measures 3.2 inches in diameter and 7.3 inches long; weighs 2.4 pounds; 1-year warranty