This rack holds large conical and round-bottom centrifuge tubes that cannot stand up by themselves. The epoxy-coated steel wire rack is 4" high and has two levels of square grids to hold 6 tubes up to 250mL (60mm diameter). Heat-cured epoxy coating is unaffected by organic solvents, salts, weak acids and weak alkalis. Temperature range: -223°C (-369°F) to 121°C (250°F). Autoclavable.