A breathing circuit system for supplying a breathable gas from a breathable gas supply system to a patient interface. The system comprises a heated conduit, comprising a hose and a hose heating system associated with the hose, and a plurality of adapter elements. The hose heating system is provided for operating within a first predetermined voltage range. A controller is associated with the breathing circuit and provides voltage within a second predetermined voltage range. Each adapter element comprises at least one electric component provided for adjusting the voltage supplied by the controller from a second range to the first range.