CryoKing 3.75 Inch 81-well Cryo Boxes, Lab Freezer Boxes with Connected Lid, ID-Color Cardboard Freezer Boxes with Straight Grid Divider, 20 /Case

Made of durable cardboard with a waterproof coating and polypropylene dividers Made of durable cardboard with a waterproof coating and polypropylene dividers Alphanumeric labeling featured on the lid, bottom and four sides enables quick and easy identification of samples Holds 5.0ml microtubes and cryogenic vials Working temperature: stable from -86°C to 121°C Suitable for liquid nitrogen freezing(vapor phase) (after adding vent holes, and using cardboard dividers)