This pack of 25 Pyrex test tubes (model no. 9825) are perfect for laboratory use. Made of high-quality borosilicate glass in the United States, these graduated cylinders are reliable and durable. Measuring 16mm x 150mm and holding 30ml, they are ideal for a variety of experiments and procedures. The screw top is not included, but can easily be obtained separately. These test tubes are a must-have for any laboratory, medical, or dental facility.