Schott/Duran® clear borosilicate glass media bottles are resistant to chemical attacks and thermal shock, and they can be sterilized to 140°C. Keep Caps loosened when autoclaving. Bottles feature a graduated scale and labeling panel. All bottles are equipped with pouring rings to eliminate dripping and to protect the rim of the bottle. The screw-cap has a molded-in seal ring to ensure a tight and dependable seal. Compare with Corning's orange cap #1395 series and save. Our Screw Cap is blue in color.