Abdos Cryo Vial external thread are manufactured using high purity virgin USP Class VI Medical grade polypropylene (PP) conforming to US FDA 21 CFR, free from natural rubber & heavy metal. Abdos Cryo Vial is designed for long-term cryogenic storage of biological samples, all type of cells and any enzymes or reagents. It’s leak-proof cap design and strong wall thickness makes it an ideal product for transporting samples and specimens. These cryo vials are designed for mechanical freezing and it’s a screw cap reduces the risk of contamination due to handling.