This product is a dedicated APO teleconverter that can be mounted between select lenses and the camera body to increase the focal length by the power of 1.4. It is compatible with the lens autofocus function, depending on the open-aperture F value of the lens being used, and it works with the AE (Automatic Exposure) function, dispensing with complicated exposure calculations. It also offers maximum photography magnification by 1.4x, without any variation in the minimum focusing distance. Compact and lightweight, this teleconverter converts your lenses into longer focal-length lenses, so you don't have to do a lot of unnecessary footwork.