***** **********Best Quality Guranteed. *****It comes with 2pcs 16 inch long industrial 15mm aluminum rods*****The diameter of the DSLR rail rod is 15mm standard*****This 15mm camera rod is essential for Rod Support System, Matte Box, Rig Cage Handle, Follow Focus mounting on the rods*****Inner thread is M12 female thread on each end of a rod so that you could extend the tubes with a M12 threaded connector*****Made of Aluminum Alloy, durable yet lightweight