Get a jumpstart on your next science experiment with Test Tubes, Rack + More Glass Kit. A great basic kit, featuring some of the most common tools found in all labs. The glass test tubes are made from borosilicate glass tubing with uniform wall thickness for maximum heat transfer and chemical resistance. The 4-way test tube rack is sturdy and can be used for other size test tubes, even the large Safety Test Tubes or "preforms". Having the right tools is sure to make your experiment easier and safer.