This Bel-Art test tube rack is a reliable and sturdy unit with a capacity to hold 72 test tubes with a diameter of up to 20 mm. It is manufactured in the United States, making it a high-quality product. The no-wire grip feature ensures that the tubes stay in place and do not slip off, providing stability and safety during experiments. This rack is suitable for use in physical, dental, medical, and biological laboratories and is a great addition to any lab. The unit comes with 40 holes, making it perfect for holding 13mm tubes and smaller. The Bel-Art test tube rack is the perfect choice for anyone looking for a reliable and practical solution to store and organize their test tubes.