It are designed for securely holding test tubes with a diameter of 16 mm. Made from durable polycarbonate (PC), these stands are built to withstand heavy use in laboratory environments. The 4x10 configuration allows for efficient organization and storage of up to 40 test tubes, making them an ideal solution for labs that require convenient and space-saving storage for their test tubes. Whether used in research, analytical, or educational labs, these stands provide reliable support for your test tubes during experiments or sample handling.