Cryo Tube provided by STE-Mart is made of medical grade PP material. It is ideal for storage of biological sample in the labs. In the gas situation of liquid nitrogen, it can withstand temperature as low as -196℃. Silicone gel O-ring in the cap ensures no leakage, even in the standard lowest storing temperature, which will guarantee the sample safety. Different inserted color top will help easy identification. White writing area and clear graduation allow easy marking and volume calibration more convenient.