Canon 2x extender for EF lenses. Designed to extend a lenses focal length by a factor of 2x, the redesigned Canon Extender EF 2X III delivers optical performance on par with the finest Canon super telephoto lenses. This lens is only compatible with fixed focal length L-series lenses 135mm and over, as well as the EF 70-200/2.8L, EF 70-200/2.8L IS, EF 70-200/4L, and EF 100-400/4.5-5.6L

• Canon Extender Cap E II
• Canon EF Rear Lens Ca