Abstract: A coupling device for supply lines is used in particular for conveying media from a tractor to a semi-trailer (11) or vice versa. The tractor and the semi-trailer (11) can be coupled and uncoupled by means of a coupling unit (10), which comprises a fifth wheel coupling (15) on the tractor and a support element (22?) with a king pin (21) on the semi-trailer (11). Below the fifth wheel coupling (15) and below the king pin (21), there is at least one coupling block (30, 31) each, the coupling blocks each being provided with a plurality of connector elements (37, 38, 77, 78) for connecting the supply lines (33, 34, 35, 36). A rotary element (20) disposed in the support element is provided, to which rotary element the at least one coupling block (30, 31) and a centering device (25) are fastened.