An apparatus for transferring a fluid from and/or to a system, e.g., an air conditioning system, includes a main compartment having at least one pumping device for pumping the fluid from/to the system, an interface module having at least one gauge which is configured for displaying the pressure of the fluid, and a fluid connection fluidly connecting the gauge to the main compartment. The fluid connection is formed in a double conduit design in order to prevent any leakage of the fluid from the fluid connection.