Desmond 180mm Nodal Slide DNR-180 Dual Dovetail Macro Rail & Clamp Arca Compatible All Metal (aluminum) Construction No Rubber or Plastic Parts. Compatible with all Arca style clamps, including RRS Lever Clamps. Includes bubble Level & precision decimal scale. Precision rail. Ideal for panoramas. Includes 1 x 1/4" hex screws, 2 x safety screws and 2 allen wrenches.