These bins are made from heavy-duty FDA approved polypropylene. The wide stacking ledge allows for high stacking, and reinforced design prevents spreading. A built-in rear hanger allows bins to hang from louvered panels or rails. They will not rust or corrode, and are unaffected by weak acids, alkalis, and are waterproof. These bins are designed to be interchangeable with other manufactured brands of bins. Autoclavable up to 250 DegreeF and resistant to extreme cold. Dividers are available to keep contents organized. The large label slot provides easy insertion for parts identification.