These rugged autoclavable storage boxes are molded in polycarbonate, and can be used at temperatures of -150°C to 121°C. Designed to hold 100 each 0.5ml microcentrifuge tubes, or 64 each 1.5ml tubes. The numbered grid on transparent lid is keyed in one position to prevent misalignment. Lid accepts writing with a marker. Not recommended for use with liquid-phase liquid nitrogen.