COMPATIBILITY - RF 600mm F11 IS STM / RF 800mm F11 IS STM / RF 100-500mm F4.5-7.1L IS USM / RF 400mm F2.8L IS USM / RF 600mm F4L IS USM / RF 100-400mm F5.6-8 IS USM / RF 800mm F5.6L IS USM / RF 1200mm F8L IS USM / RF 200-800mm F6.3-9 IS USM MORE REACH - The extender features high-refraction, low-dispersion glass to control curvature of field and chromatic aberration of magnification for the highest image quality. ADVANCED LENS DESIGN - As well as optimised lens coatings, a 3-layer combined lens helps to reduce ghosting by reducing the surfaces in contact with the air as much as possible. PERFORM IN EXTREMES - The exterior is coated in the same white heat shield coating as used on the RF 100-500mm F4.5-7.1L IS USM and RF 70-200mm lens to prevent deterioration in performance in high temperatures. WATER RESISTANT - Designed for reliability and durability with vibrational shock resistance plus dust and water resistance for use by professionals and high-end amateurs.