" http://www.amazon.com/gp/product/B000053HH5?tag=httpblogtrave-20
70-200mm telephoto zoom lens with f4 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 f4L USM lens
39-foot close-focusing distance supports use of circular polarizing filter
Measures 3 inches in diameter and 68 inches long weighs 25 ounces 1-year warranty
Canon EF 70-200mm f/4L USM Telephoto Zoom Lens for Canon SLR Cameras"