Endotracheal Tube Stylets. Plastic coated malleable metal wire. One end has a rubber stopper that fits tightly over the endotracheal tube connector, sliding to adjust for proper length. Available in three sizes to suit a range of tube sizes. Small (2.0-3.5mm Tubes), Medium (4.0-6.5mm Tubes) or Large (7.0-10.0mm Tubes).