Tronixpro 52mm Pro Series Snap On Lens Cap For Pentax smc DA 50mm f/1.8 Lens, Pentax DA 18-55mm f/3.5-5.6 AL WR Zoom 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 52mm Snap On Lens Cap