Extend the reach of your existing Canon EF and EF-S mount lenses with this Autofocus 2x Teleconverter from Fotodiox. This converter doubles the effective focal length of your lens, turning a 50mm lens into a 100mm optic for example. It also maintains communication between the lens and camera and uses multi-coated optics to limit ghosting and flares. Additionally, the four element design ensures sharp imagery. This converter is compatible with most EF and EF-S lenses and cameras, though there is a light loss of about 2 stops during use.