1. smooth walls and good transparency 2. tightly sealed lid, no sample evaporation 3. easy to read liquid volume with 0.5-2ml calibration 4. low temperature resistant, can be frozen for a long time 5. used in hospitals, epidemic prevention stations, schools, research laboratories, etc. Specifications: Description: : This test tube is suitable for all kinds of freezing experiments. It can stand upright and the lid can be unscrewed with one hand for easy and convenient operation. Features: The walls of the tube are smooth and the transparency is good. The cap is well sealed and the sample does not evaporate. 0.5-2ml calibration function, easy to read the liquid volume. Resists low temperatures and can be frozen for long periods of time. Used in hospitals, epidemic prevention stations, schools, research laboratories, etc.< /p> Specifications: Lids are shipped in random colors (white, blue, red, yellow, green, orange). If you need a specific color, please add a note. Or contact customer service. The lyophilization tubes are made of polypropylene PP, which can be sterilized at high temperature and can be placed in refrigerators at -80 degrees to freeze samples. The scale shown is available in 2ml or 1.8ml , please specify when ordering. Both scales are identical, but the graduations are different. Package includes 1 bag (100 tubes) x 1 tube Attention 1) Due to manual measurements, please allow 1-3mm error. Thank you for your understanding. 2. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real thing. Please refer to the actual item as the standard.