The GVP-MI(R) provides a continuous adapting seal preventing leakage, stabilising the endotracheal tube and thus reducing movement of the tube within the larynx and trachea.
 
It is suggested that a plain endotracheal tube of the largest diameter that will permit leakage of gases around it , combined with a child sized General V-Pack creating a soft seal ,can be of particular value when intermittant positive pressure ventilation is used.