The LensCoat Lens Cover for Canon RF 600mm f/11 IS STM is made from stretchy, soft and shock-, water-repellent neoprene material, designed to provide maximum protection against nicks, dings, and scratches from accidental impact when out and about with your longer RF 600mm lens. The cover has a clear plastic window over the Auto Focus and Image Stabilization controls, so you don't have to guess when the cover is on.