his Cavision 67-82mm Step-Up Ring permits the use of 82mm threaded filters on lenses with 67mm filter threads. Additionally, the 12mm depth of this ring provides more surface area than a standard step-up ring. This provides a more secure grip to the clamp of your Cavision Clamp-On Matte Box. The step-up ring features a lightweight, aluminum-alloy construction that has a black anodized finish.