Extend the reach of Canon EF-mount telephoto lenses with this EF 1.4x Extender Teleconverter from Viltrox. This 1.4x teleconverter effectively increases the focal length of the attached lens by 40% while retaining autofocus and communication between the camera and the lens. The teleconverter uses a seven- element, three-group optical design to maintain high sharpness and clarity, and the individual elements have been multi-coated to reduce flare and ghosting. This teleconverter is compatible with most EF-mount lenses that have a focal length of 100mm or longer.