Heavy duty square storage containers. A space saving range of clear polycarbonate square containers, which will store up to 33% more than equivalent round containers. Polycarbonate Containers. Break-resistant clear polycarbonate for visibility and long. Break-resistant clear polycarbonate for visibility and long life. Dishwasher and freezer safe: temperature range -40 degree to +99 degree. Measurement graduations. Nests for compact storage. Can be used with E4452 Lid