Nalgene® Cryobox™ Racks Stainless steel Features an innovative retainer that holds each box securely but separately Allows fast retrieval of one box and immediate return of rack to freezer Vertical racks for chest-type freezers are available in 2, 4 and 7 shelf sizes to accommodate 5151W80 Nalgene Tall Cryoboxes and other cardboard or stainless steel storage boxes for 4.0 mL and 5.0 mL vials.