Canon EF 70-200mm f/4 L is USM Lens Canon Digital SLR Cameras International Version (No Warranty) 70-200mm telephoto zoom lens with f/4 maximum aperture for Canon digital SLR cameras Fluorite UD lens elements produce excellent optical performance in resolution and contrast Ring-type ultra-sonic monitor (USM) for quick and quiet autofocusing; lightweight construction Image Stabilizer provides up to 4 stops of shake correction; water- and dust-proof construction Measures 3 inches in diameter and 6.8 inches long; weighs 26.8 ounces