Clear 10 ml sterile vials - 5 pack. These sterile vials are Type 1 borosilicate assembled with butyl stoppers and colored aluminum seals, colors may vary. Neck size is 20mm. Sterilization is performed in an FDA inspected facility, operating to cGMP compliance. All sterilization processes are carried out under strict Class 100 U.S. Pharmacopoeia and Federal Code of Regulations methodologies. Assembled units are sterile and free of all endotoxins and meet the FDA's mandated 14-day sterility testing protocol. Perfect for HCG mixing!