This connector adapter is for connections from users such as lights to a switched mode power pack with a 4-pin mini DIN high current plug.

In normal words, if you have a 60065 power supply, this is the female plug with wires that will fit the 4-prong plug. You need it if you want to power other items with this supply then a Central Station.

Also suitable to use the Marklin 60195 with older LGB controllers.