in the sleeve shaped body an internal thread is provided by which the connector can be screwed onto a threaded connection relative to axial extension the locking groove and locking rib serving to hold the connector in the coupler are located at the height of the thread that is the locking rib and locking groove located ahead of the thread in the state of the art have moved to the region of the thread in the arrangement according to the invention application_number US 57414809 A description fig1 shows a fluid coupling arrangement 1 in the uncoupled state the coupling arrangement 1 includes a coupler 2 and a plug 3 according to the invention that can be plugged into the coupler 2 the plug 3 has a sleeve like body 4 which is provided with an inner thread 5 with the aid of the inner thread 5 the body 4 can be screwed onto an outer thread 6 of a cylinder valve of which only the thread support 7 can be recognized the outside of the body 4 has rotation symmetry and carries at its back end i e at the end away from the coupler 2 a hexagon 8 as a tool gripping surface directly adjacent to the hexagon 8 a circumferential groove 9 with a trapezoidal cross section is present which goes over to the insertion end of the plug 3 into a rib 11 when connected to the rib 11.