AquaTech Soft Cap ASCC-5 for Canon 500mm f/4 is Lens The AquaTech Soft Cap ASCC-5 is a light and practical alternative to the leather style lens caps that are delivered with Canon and Nikon's big telephoto lenses Constructed from a pliant waterproof silicon material, the Soft Cap makes a snug fit right at the end of the lens barrel without contacting the glass This simple yet effective product is the perfect protection for your valuable glass. This SoftCap can also be combined with AquaTech's SoftHood collapsible fabric hoods Suitable for the following lenses: Canon 500mm f/4 IS - Canon 500mm f/4 IS II