The Micro Clamp - 15mm for Really Right Stuff is an adapter for Really Right Stuff quick-release plate and dovetail. It adapts with the Really Right Stuff clamp for camera or lens mounting and adjusts HDSLR at proper height, hence can be used with rail-mounted accessories such as matte box, follow focus, etc.
In addition to enabling the use of "L" bracket camera plates for vertical shooting, the Clamp - 15mm makes use of industry-standard 15mm/60mm spacing rails. Enhanced standards-based solution offers maximum compatibility for the unit. It is virtually compatible with all rigs and Really Right Stuff B2 LR II quick-release clamp.