Made of medical grade polypropylene Autoclavable Can be repeatedly frozen and thawed Universal screw threads ?Vials fit most common rotors Vials fit standard 1-inch and 2-inch freezer boxes Gamma radiation sterilized DNase & RNase free, endotoxin free, and human DNA free 81-8204 2ml self-standing vials have a white writing area and black graduation mark ?O-ring caps Working Temperature: -86??C ~ 121??C 50 Pcs/Bag, 500 Pcs/Pack, 2000 Pcs/Case