The polypropylene Flex-Tube® opens easily with one hand, yet remains tightly sealed during centrifugation. The flexible collar is designed to minimize the splashing of materials. Excellent for centrifugation and storage of samples, but it is not recommended for high-temperature incubation. Autoclavable at 121°C. Withstands forces to 25,000 g. Etched side writing surfaces and flat top allow easy sample identification. Tubes hold 1.5 ml.