Two suction devices – by vacuum and by ejector with pressurized air – are available. With vacuum suction, the underpressure is generated by a central vacuum pump where the vacuum regulators are directly coupled to the tapping unit. The ejectors are based on the Venturi principle where underpressure is generated with pressurized air. The ejectors are coupled to the corresponding gas outlets for pressurized air. Both systems are designed for various underpressure applications (continuous drainage, bronchial suction). The devices are easy to clean and low-noise in operation.