Canon EF 100-400mm f/4.5-5.6L IS USM Telephoto Zoom Lens for Canon SLR Cameras 100-400mm telephoto zoom lens with f/4.5 maximum aperture for Canon SLR cameras 2 Image Stabilizer modes make it easy to capture far-off action or close-in portraits Flourite and Super UD-glass elements largely eliminate secondary spectrum Compatibility with extenders 1.4x II and 2x II; 5.9-foot close focusing distance Measures 3.6 inches in diameter and 7.4 inches long; 1-year warranty