The Canon EF 70-200mm f/4.0L USM Lens is a high-performance, L-series telephoto zoom lens combining light weight 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. Features: EF mount; telephoto zoom lens Ultra-low Dispersion glass with Fluorite elements; inner focusing ring; full-time manual focus 70-200mm focal length f/4.0 constant maximum aperture Ring-type UltraSonic Motor (USM)