An add-on device for an Endo-Tracheal Tube, ETT, the add-on device comprising: a lengthy body having a major arc-shaped cross section sized and shaped to tightly fit over an ETT; at least one longitudinal cavity passing along the lengthy body, comprising a distal suction cavity ending with a suction inlet at a distal end of the lengthy body; a distal suction outlet channel extending from a proximal end of the lengthy body, the channel is a continuous extension of the distal suction cavity and configured to provide suction to the distal suction cavity; characterized in that the add-on device comprises: a moisture sensor for detection of liquid at the distal end of the lengthy body; sensor data wires connected to the moisture sensor and to a controller; a hub for operating the add-on device, the hub comprising the controller; wherein the lengthy body includes a core of thickness between an external and an internal perimeters of the lengthy body, wherein the sensor data wires pass within the core; wherein the controller is configured to control suction supply to the distal suction outlet channel according to moisture sensor data received from the moisture sensor via the sensor data wires, by operating a pinch valve, wherein the add-on device is adapted for installation on the ETT with minimal or no interruption to the ventilation process, for removal of excessive fluids and secretion from the trachea and mouth during the ventilation by the ETT with no need to replace a currently installed ETT. a lengthy body having a major arc-shaped cross section sized and shaped to tightly fit over an ETT; at least one longitudinal cavity passing along the lengthy body, comprising a distal suction cavity ending with a suction inlet at a distal end of the lengthy body; a distal suction outlet channel extending from a proximal end of the lengthy body, the channel is a continuous extension of the distal suction cavity and configured to provide suction to the distal suction cavity; characterized in that the add-on device comprises: a moisture sensor for detection of liquid at the distal end of the lengthy body; sensor data wires connected to the moisture sensor and to a controller; a hub for operating the add-on device, the hub comprising the controller; wherein the lengthy body includes a core of thickness between an external and an internal perimeters of the lengthy body, wherein the sensor data wires pass within the core; wherein the controller is configured to control suction supply to the distal suction outlet channel according to moisture sensor data received from the moisture sensor via the sensor data wires, by operating a pinch valve, wherein the add-on device is adapted for installation on the ETT with minimal or no interruption to the ventilation process, for removal of excessive fluids and secretion from the trachea and mouth during the ventilation by the ETT with no need to replace a currently installed ETT. a moisture sensor for detection of liquid at the distal end of the lengthy body; sensor data wires connected to the moisture sensor and to a controller; a hub for operating the add-on device, the hub comprising the controller; wherein the lengthy body includes a core of thickness between an external and an internal perimeters of the lengthy body, wherein the sensor data wires pass within the core; wherein the controller is configured to control suction supply to the distal suction outlet channel according to moisture sensor data received from the moisture sensor via the sensor data wires, by operating a pinch valve, wherein the add-on device is adapted for installation on the ETT with minimal or no interruption to the ventilation process, for removal of excessive fluids and secretion from the trachea and mouth during the ventilation by the ETT with no need to replace a currently installed ETT.