An arrangement for installation in a fluid line network contains a fluid meter having a housing with a fluid inlet and a fluid outlet, and a volume measuring part. At least one connector, which is intended for connection to the housing of the fluid meter, is either equipped with an additional function or configured for the adaptation of an additional function on the connector. The connector has a connector inflow and a connector outflow. The fluid meter and the connector form a modular unit that can be installed in the fluid line network.