Endobronchial blocker tube is a device which can be inserted down a tracheal tube after tracheal intubation so as to block off the right or left main bronchus of the lungs in order to be able to achieve a controlled one lung ventilation. The lung tissue distal to the obstruction will collapse, thus allowing the surgeon’s view and access to relevant structures within the thoracic cavity. Our blocker tubes are used to achieve lung separation and one lung ventilation as an alternative to Double-lumen tubes(DLT) and serve as a choice for pediatric patients as well.