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 to infinity; supports EF Extender 1.4x and 2x. Measures 3.2 inches in diameter and 7.3 inches long. Minimum Focal Range: 18.9 inches. Maximum Aperture Range: F/3.5. Camera Magnify Power: 1/1. Lens System Special Functions: Macro. Focus Type: auto-focus manual-focus. Real Angle Of View: 13.5. Item Display Diameter: 3.3 inches. Length: 7.