CELLTREAT Freeze Cryogenic Vials are designed for storing biological material at temperatures as low as -196°C, in the gas phase of liquid nitrogen,Available in round bottom or self-standing options,CELLTREAT product descriptions are based on the highest graduation mark on the vial. Other brands may name vials based on actual liquid capacity,Self-standing re-sealable bags offer a unique storage solution,Internal thread cap prevents contamination and uses O-ring silicone seal to ensure positive seal at any temperature.Caps have textured ridges to provide gripping when wearing gloves.Contrasting black graduations are large and easy to view.Large white marking area for writing also provides backdrop to enhance black graduations.Self-standing base interlocks with Easy Grip Workstation Rack for easy one-handed opening