Autoclavable polypropylene boxes keep samples in 50 ml tubes protected and neatly organized. Each tube is supported by a sturdy grid with easy-to-read cell numbers. The transparent lid protects the tubes while allowing you to clearly see cap labels and tube positions. If a tube cracks, any spilled liquid will be contained by the solid base. Each closed box measures 5.67" W x 5.67" D x 5" H. Suitable for use from -80°C to +121°C.