• 70-200mm telephoto zoom lens with f/4 maximum aperture for Canon SLR cameras.
• Inner focusing system and ring-type ultra-sonic monitor for quick and quiet autofocusing.
• Compatible with same tripod collar (sold separately) as EF 300mm f/4L USM lens.
• 3.9-foot close-focusing distance; supports use of circular polarizing filter.
• Measures 3 inches in diameter and 6.8 inches long; weighs 25 ounces; 1-year warranty.Lens Construction:16 elements in 13 groups.

Product Description ------------------- Canon EF 70-200mm f/4L USM Telephoto Zoom Lens for Canon SLR Cameras. What's in the box: E-67U 67mm Snap-On Lens Cap Lens Dust Cap E (Rear), ET-74 Lens Hood, LP1224 Lens Case, 1-Year Warranty. Filter size: 67 mm, Closest Focusing Distance: 3.9 feet. From the Manufacturer --------------------- Capture the far-off action of fast-paced sports or zoom in for an portrait with the Canon EF 70-200mm telephoto zoom lens. This high-performance, L-series telephoto zoom lens is distinguished by such features as an f/4 maximum aperture, an inner focusing system, and a ring-type ultra-sonic monitor (USM). The last two features combine to deliver quick and quiet autofocusing--a priority for many amateur and professional photographers. In addition, photographers can attach and use a circular polarizing filter without difficulty because the front lens element does not rotate during focusing. Compatible with the same tripod collar (sold separately) used with the EF 300mm f/4L USM lens, the lens carries a one-year warranty. * Focal length: 70-200mm * Maximum aperture: 1:4.0 * Lens construction: 16 elements in 13 groups * Diagonal angle of view: 34 to 12 degrees * Focus adjustment: Inner focusing system with USM * Closest focusing distance: 3.9 feet * Zoom system: Rotating type * Filter size: 67mm * Dimensions: 3.0 inches in diameter, 6.8 inches long * Weight: 25 ounces A truly professional L-series telephoto zoom lens, with reduced size and weight for applications where portability is important. Superb optically, it combines a Fluorite element with two UD-glass elements for outstanding contrast and performance. Its ring-type USM is fast, silent, and permits full-time minimum focus, as well as the closest MF of any of the L-series 70-200 designs. Itís also compatible with EF Extenders 1.4x II and 2x II, and accepts an optional accessory tripod collar. Isolate the Interesting Part The eye tends to see the whole rather than the individual parts. It also sees whatís near and not whatís far. By bringing attention to those things missed by the eye, you can create many interesting pictures. It could be the grimace of an athlete, the grill of a classic car, or a girl against a blurred background. Telephoto lenses can also compress images to give dramatic effects. You are limited only by your imagination.