 "Canon EF zoom lens 70-200mm" " Canon 70-200mm - 2578A002 Camera & Camcorder Lenses CDW.com
"High-performance, L-series telephoto zoom lens combining lightweight and compactness with an f/4 maximum aperture. Inner focusing and the ring USM enable quick and quiet autofocusing. Also, a circular polarizing filter can be attached and used without difficulty because the front lens element does not rotate during focusing. The tripod collar (sold separately) is the same one used with the EF 300mm f/4L USM." 
 "Canon EF telephoto zoom lens - 70 mm 300 mm" " Canon 4426B002 Camera & Camcorder Lenses CDW.com
"Designed to deliver ultra-high quality images along with lightning fast operation, the Canon EF 70-300 f/4-5.6L IS USM telephoto zoom lens brings a favorite zoom range to the celebrated Canon L-series of lenses. It features two Ultra Low Dispersion (UD) elements for improved image quality and reduced chromatic aberration, incorporates a floating focusing mechanism for sharpness from close up to infinity, plus an IS system that increases usability by approximately four stops. The EF 70-300 f/4-5.6L IS USM features a function that prevents erroneous operation when the lens is mounted on a tripod or monopod. Gleaming white, with a removable tripod collar, dust and water resistant construction, and a newly developed Fluorine coating that keeps soiling, smears and fingerprints to a minimum, its phenomenal performance and flexibility is assured. For portraiture or to bring what's far away up close, this addition to the L-series is guaranteed to perform." 