Sentinel Seal™ Chest Drainage Unit, Dry Suction, Dual Drain is effective for reestablish normal lung function. Sentinel Seal™ Chest Drainage Unit, Dry Suction (CDU) connect four chamber for monitoring volume, rate, and nature of drainage. A water-seal chamber performs as a one-way valve and a window into the patient’s pleural space. Blue-Colored Patient Assessment Manometer Monitors provide you real time negative pressure readings. A dry suction mechanical regulator is for control suction. It also convenient for re-expand the lung.