Designed for the storage and transportation of biological material. Manufactured from non-toxic polypropylene, the tube provides strength and clarity and exhibits some unique design features. The vial has external threads, providing a smooth and uniform inner surface, thus reducing the risk of contamination. Tubes can be autoclaved (121 °C) in upright position with caps loosened. Height of tube is with cap. Round bottom tubes only can be centrifuged up to 17,000g. Order caps separate. Made of polypropylene.