Super telephoto L-series lens with an Image Stabilizer for use in sports as well as low-light nature, wildlife photography and fashion. The fluorite element and two UD-glass elements result in high resolution and high contrast. The ring USM and an improved AF drive algorithm make the AF speed the fastest in the world when used with 1 series bodies. The lens is compatible with 1.4x and 2x extenders (available to rent) to achieve even longer focal lengths.