A catheter used for endotracheal intubation. The distal opening is 45°, with an inflatable balloon. After the balloon is inflated, the gap between the catheter and the tracheal wall is blocked to ensure the tightness of mechanical ventilation. According to the material, it can be divided into rubber tube, plastic tube and silicone tube. https://www.rollmed.net/medical-...ce-and-professional.html