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°C o M easurement graduations o N ests for compact storage . Can be used with E4477 Lid