***** **********Best Quality Guranteed. *****The diameter of the camera rod is industrial 15mm standard*****The 4in 15mm rod is widely used on camera riser system and movie making accessories, such as lens support, matte box, follow focus, etc. *****M12 inner thread on each end of a rod allows you to use a M12 threaded connector to lengthen the rod as you want*****Comes with 2pcs 4 in 15mm rods, well machining and finish*****Black anodized aluminum alloy, durable to last long