Snap cap design that it 't be opened accidentally, not easy to leak and safe to use Used in molecular biology, clinical chemistry and Bio-chemistry research, perfect for working with delicate samples, storing tiny specimens The vial tubes are designed with clear scale on tube body, which facilitate accurate sampling,easy to observe Made of High transparency PP material, apply to Micro-centrifuge, disposable perfect for many fields,like lab experiment and home use for taking certain volume liquid