Tronixpro 77mm Pro Series Snap On Lens Cap For Canon EF-S 17-55mm f/2.8 IS USM Lens, Canon EF 70-200mm f/2.8L USM Lens, Canon EF 24mm f/1.4L II USM Lens This lens cap protects lens surface from dust & shock during storage. Unique snap on design allows easy installation onto the lens & one-step removal from the lens. It fits directly onto the lens with a double-action spring design. Microfiber Cloth 77mm Snap On Lens Cap