Changeover installation for coating media, in particular for paints, having a) a plurality of supply units, each of which has at least one inlet connector, which is connectable to a reservoir, and an outlet connector, a flow duct extending between said connectors; b) at least one coupling unit which has an entry connector and an exit connector which is connectable to an application installation, a passage duct extending between said connectors; c) a positioning installation by means of which the coupling unit in at least one positioning movement direction is movable relative to the supply units; wherein d) the entry connector of the coupling unit is complementary to the outlet connectors of the supply units in such a manner that the entry connector of the coupling unit in a coupling movement direction is movable relative to one of the supply units, and is couplable to the outlet of said supply unit, and is separable from said supply unit again; e) the coupling unit comprises a locking installation by means of which the entry connector of the coupling unit is capable of being locked to one of the outlet connectors of the supply units; f) the supply units have locking means which interact with the locking installation of the coupling unit, characterized in that g) the locking installation of the coupling unit comprises one or a plurality of locking elements having a mushroom-shaped lock-bar end, and the outlet connector of the supply unit has a connector face and a locking side that faces away from said connector face, wherein a plurality of locking passages that are complementary to the lock-bar ends of the one or the plurality of locking elements have an ingress portion and a locking portion that is narrower in comparison to said ingress portion. a) a plurality of supply units, each of which has at least one inlet connector, which is connectable to a reservoir, and an outlet connector, a flow duct extending between said connectors; b) at least one coupling unit which has an entry connector and an exit connector which is connectable to an application installation, a passage duct extending between said connectors; c) a positioning installation by means of which the coupling unit in at least one positioning movement direction is movable relative to the supply units; wherein d) the entry connector of the coupling unit is complementary to the outlet connectors of the supply units in such a manner that the entry connector of the coupling unit in a coupling movement direction is movable relative to one of the supply units, and is couplable to the outlet of said supply unit, and is separable from said supply unit again; e) the coupling unit comprises a locking installation by means of which the entry connector of the coupling unit is capable of being locked to one of the outlet connectors of the supply units; f) the supply units have locking means which interact with the locking installation of the coupling unit, g) the locking installation of the coupling unit comprises one or a plurality of locking elements having a mushroom-shaped lock-bar end, and the outlet connector of the supply unit has a connector face and a locking side that faces away from said connector face, wherein a plurality of locking passages that are complementary to the lock-bar ends of the one or the plurality of locking elements have an ingress portion and a locking portion that is narrower in comparison to said ingress portion.