Canon EF 100-300mm f/4.5-5.6 USM Telephoto Zoom Lens for Canon SLR Cameras
The Canon EF 100-300mm lens completes a fusion of state-of-the-art  electronics, mechanical precision, and optical excellence. The fully electronic  EF lens mount is unique among 35mm SLR cameras, operating silently and reliably  due to the complete elimination of mechanical couplings. It has a custom- designed autofocus motor and microprocessor, and employs ultrasonic motor  technology, aspherical lens elements, flourite crystal and ultralow-dispersion  glass. The EF 100-300mm is designed for use with all EOS cameras, allows auto  and manual focus modes, rear focusing system, and has an affordable price.