These reliable and robust extenders match the performance of Canon RF lenses and deliver uncompromising imaging performance when used with compatible lenses. Both extenders feature lenses made of high-refractive-index glass with low dispersion. This counters field curvature and chromatic aberrations, ensuring excellent image quality. They also offer lens coatings and a three-layer combination lens to reduce ghosting. The extenders are equipped with a heat protection coating that prevents performance degradation at high temperatures and support the weather resistance of a compatible RF lens from the L series. When used with the RF 100-500mm F4.5-7.1 L IS USM, the zoom range is limited to 300-500mm when the extender is attached.