A space divider of a milking parlor arrangement for at least one milking parlor for milking milk-producing animals, wherein the space divider is arranged approximately parallel to a longitudinal axis of the animal to be milked, has an arm device having a milking cluster, which can be adjusted from a parking position to a working position and back. The arm device is arranged with the milking cluster in the parking position in the space divider and can be adjusted into the working position laterally to the animal to be milked between the front and rear legs thereof. The space divider may include a replaceable service unit.