Opteka 500mm f/6.3 (with 2x- 1000mm) Telephoto Mirror Lens for Digital
Amazon.com : Super-Powered 500mm/1000mm f/8.0 Manual Telephoto Lens (Black) with 2X Professional Multiplier for Canon EOS Digital SLR Cameras and Deluxe Accessory Bundle with Xpix Cleaning Kit : Electronics