The Canon Extender EF 2X III is designed to double a lens’s focal length while maintaining optical quality comparable to Canon’s best 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.