It comes with a 1/4inch thumb screw, it is used to install the cable clamp on cameras This cable clamp is used to fix the cable when you are in Tethers. It protect the adapter of the camera and ensures it will not been interrupted by cable loosening There are two grooves in horizontal and perpendicular separately for cable. It is suitable for all most of DSLR Cameras This cable clamp is also used for DSLR camera cage There is a 1/4inch threaded hole on the thumb screw.it is used to connection with your quick Releasing plate for tripods