Canon EF Extender 2x III
The EF 2.0x III serves as the perfect accessory to Canon EF Lenses allowing you to get even closer to the action capturing that perfect shot. The Extender EF 2x III is specially designed to work in conjunction with L-series IS super-telephoto lenses, extending their focal length by a factor of 2x. The extender's design ensures there is no loss of lens performance or image quality.
This extender 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. AF compatibility also depends on the combination of the above lenses and DSLR