The RRS-9000511 Multi-Purpose Cinema Rail by Really Right Stuff delivers a vast array of mounting options for cameras and accessories. The top and bottom sides feature 1.5” dovetails which are compatible with all Relay Right Stuff quick-release clamps, as well as 1/4”-20 and 3/8”-16 threaded sockets spaced 15mm apart. The sides also feature 1/4”-20 threaded sockets spaced 9mm apart. In addition, the RRS-9000511 Multi-Purpose Cinema Rail is 14% lighter per inch and 25% stiffer than traditional camera rails, and the top is laser engraved with markings every 5mm to make repeat setups easy. Features of the RRS-9000511 Multi-Purpose Cinema Rail: Double dovetail rail accepts 1.5" Dovetail clamps on top and bottomLaser engraved at 5mm increments (starting at 0mm from each end)Includes alternating 1/4"-20 and 3/8"-16 threaded sockets spaced 15mm apart top and bottomIncludes 1/4"-20 threaded sockets spaced 9mm apart on the sidesNote: Not compatible with accessories designed for the RRS CB-10, CB-18, and CB-28 camera bars Really Right Stuff Multi-Purpose 21.3"/540mm Cinema Rail RRS-9000511