This polypropylene test tube rack holds up to 31 test tubes up to 13mm in diameter. The 3-tier design provides a clear view of tube contents and allows convenient insertion and removal. The rack measures 10.6 inches long, 2.5 inches wide, and 4.3 inches tall. The polypropylene construction is autoclavable and durable. Suitable for professional laboratories, science classrooms, and household applications including kitchen utensil and spice storage, craft material organization, and pen/pencil holding.