This Canon EF 100-400mm f/4.5-5.6L IS USM Autofocus Lens offers high resolution, superb contrast, neutral color balance, and Canon's original built-in Image Stabilizer function. High zoom magnification is achieved by means of a 6-group configuration with 5 movable groups. Fluorite and Super UD glass completely eliminate secondary spectrum for superb color rendition. Autofocusing is fast and silent with Canon's ring USM, and AF speed is further enhanced through an advanced, lightweight rear focusing design that incorporates a floating element for consistent image quality at all focusing distances from 5.9' to infinity. This lens is also equipped with a dual-mode Image Stabilizer suitable for panning as well as stationary subjects. With full-time manual focus, one-touch zooming with a wide grip, and a special ring that permits adjustment of zooming friction, this is a lens that's extremely easy to use, and ideal for a wide variety of applications including nature, wildlife, sports, and documentary photography.