Desmond 250mm DLR-2502 Double Macro Rail Arca Compatible with Bubble Level 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. Weight: 205g Includes 2 x 1/4" hex screws, 2 x safety screws and 2 allen wrenches.