A visualization device for confirming proper positioning and placement of an endotracheal tube within a patient without requiring the use of a laryngoscope or bronchoscope, the device comprising: a visualization tube adapted to be inserted within an endotracheal tube, the visualization tube having a closed distal end, an open proximal end, and a lumen extending from the proximal end to the distal end; wherein the visualization tube is sized to extend at least to the distal end of the endotracheal tube; wherein the lumen of the visualization tube is sized and shaped to removably receive a visualization scope; wherein the closed distal end of the visualization tube comprises a window; wherein the visualization tube comprises at least one centering assembly mounted on an outer surface of the visualization tube, the at least one centering assembly comprising two or more flexible arms adapted to expand to conform to an inner wall of the endotracheal tube, thereby centering the visualization tube within the endotracheal tube; a coupling assembly adapted to couple the visualization tube to the endotracheal tube; and a scope retention assembly coupled to the coupling assembly; wherein the scope retention assembly comprises a stretchable elastomeric sleeve and a scope retention member attached to a proximal end of the elastomeric sleeve adapted to interface with a locking member coupled to a visualization scope; wherein the elastomeric sleeve is adapted to be stretched to allow the scope retention member of the scope retention assembly to engage the locking member, thereby exerting a static force on the visualization scope in the direction of the closed distal end of the visualization tube upon release of the elastomeric sleeve. a visualization tube adapted to be inserted within an endotracheal tube, the visualization tube having a closed distal end, an open proximal end, and a lumen extending from the proximal end to the distal end; wherein the visualization tube is sized to extend at least to the distal end of the endotracheal tube; wherein the lumen of the visualization tube is sized and shaped to removably receive a visualization scope; wherein the closed distal end of the visualization tube comprises a window; wherein the visualization tube comprises at least one centering assembly mounted on an outer surface of the visualization tube, the at least one centering assembly comprising two or more flexible arms adapted to expand to conform to an inner wall of the endotracheal tube, thereby centering the visualization tube within the endotracheal tube; a coupling assembly adapted to couple the visualization tube to the endotracheal tube; and a scope retention assembly coupled to the coupling assembly; wherein the scope retention assembly comprises a stretchable elastomeric sleeve and a scope retention member attached to a proximal end of the elastomeric sleeve adapted to interface with a locking member coupled to a visualization scope; wherein the elastomeric sleeve is adapted to be stretched to allow the scope retention member of the scope retention assembly to engage the locking member, thereby exerting a static force on the visualization scope in the direction of the closed distal end of the visualization tube upon release of the elastomeric sleeve.