One of the finest telephoto zoom lenses in the Canon EF line, with performance comparable to a single focal length lens. This high-speed lens has four UD-glass elements to correct chromatic aberrations. The constant f/2.8 maximum aperture and superb image quality make it one of the most popular professional SLR lenses in the world. An ultrasonic motor powers the autofocus system with virtually instantaneous stops and starts, while operating silently and allowing manual focusing while in the AF mode. For added telephoto power, it is compatible with Extender EF 1.4x II and 2x II. This lens is compatible with all Canon EOS digital and 35mm SLRs and focuses as close as 4.9 ft., weighs 2.9 lbs., measures 7.6" long and accepts 77mm filters. Includes case and hood.