Keep’N Box The Keep’n box storage boxes are a sustainable alternative to single-use plastic products. The range is ideal for keeping your food fresh, in the fridge or freezer. It is also microwave safe. Keep’n Box is suitable for everyday use: stackable to save space and airtight to keep food fresh. The range is available in square, rectangular and round formats. It adapts to every need with its nine different capacities. Keep’n box also includes a jug, a jar, a ham box and salad bowls.