The EF 70-200mm f/2.8L USM ;Lens from Canon is a high performance telephoto zoom lens with a constant f/2.8 maximum aperture. It has ;four UD glass elements to correct chromatic aberrations and provide overall high resolution, high-contrast images. A newly-designed inner focusing system brings high image quality throughout the zooming range and the ultrasonic autofocus motor (USM) provides fast, smooth and quiet autofocus action. This lens can focus as close as 4.9' (1.5 m). It ;includes a removable tripod collar ;and is compatible with the Extender EF 1.4x III and 2x III.