Details: RPS Studio RS-5059 Reflector Holder is a handy mounting adapter attaches to a standard light stand and mounts anything from a piece of cardboard (used to block extraneous light from getting into the picture frame) to a pop-out style reflector or background. Mouth of clamp opens up to 9 16 wide. Fits light stand spigot up to 5 8 . The entire adapter measures only 2-1 8 high and 2-7 8 long making it easy to take along anywhere.