Mr. Frosty freezing container for 4.5 to 5.0mL cryogenic tubes is made of clear polycarbonate (PC) with a blue high-density polyethylene (HDPE) lid and contains a gray HDPE vial holder, foam insert. The Mr. Frosty container provides a simple-to-use system designed to achieve a rate of cooling very close to -1°C/minute, the optimal rate for cell preservation. It holds 12 cryogenic tubes and has a profile height of 151mm (5-5/16in), which saves precious freezer space during the cooling process. The 4.75in diameter screw top closure secures samples inside in the event of accidental container tipping. The system is easy to use, and requires only 100% isopropyl alcohol and a mechanical freezer. There is no contact with the alcohol, therefore no wicking, no label removal, and no compromise of tube hand printing. Container Material: Polycarbonate. Closure Material: HDPE. Color: Clear With Blue Lid. Dimensions (O.D. x H): 117 x 151mm. Tube Compatibility: 4.5 To 5.0mL Cryogenic Tubes. Tube Capacity: 12 Tubes. Closure Diameter: 4.75in (120mm). Nalgene® #: 5100-0050.