Stopper Stopper Size 9 Neck Size 25 mm Screw Closure Size 25mm Bottom Diameter 37 mm Top Diameter 45 mm Overall Height 25 mm Material Natural Rubber Product Type Stopper Color Black Autoclavable Yes Number of Holes 1 Standards Not Applicable Special Features Low Sulfur Content Withstand Temperatures From - 25 to 70 Degrees C (-13 to 158 Degrees F) Resists Abrasion and Water For Labware Type Erlenmeyer Flasks Test Tubes Liner Material Natural Rubber Hole Diameter 5 mm