Free sample GL45 closure 500ml media bottle factory-Lab . Perfect for mixing, storing or transporting culture media, chemicals or solvents. Autoclavable Type 1 borosilicate glass. Permanent white-enamel graduations and marking spots. Approx. 30mm I.D. GL 45 screw-thread opening. Linerless blue polypropylene cap autoclavable to 140°C (284°F) and replaceable, drip-free, clear polypropylene pour ring