The test-tube stand is made of polythene and is autoclavable. It can be disassembled for easy cleaning. Stand holds 12 test-tubes, 6 holes for test tubes 30 mm diameter and 6 holes for test tubes 15 mm diameter Stand dimensions: 9 x 3.125 x 4.5 inches Stand ships flat packed 12 Hole Test Tube Stand - Holds (6) 30 mm Diameter and (6) 15 mm Diameter Test-Tubes, Made of Polythene. The stand ships flat packed and can be quickly assembled. The ability to assemble and disassemble makes it easier to clean.