Here leifheit is using modern materials to revolutionise the amount of space food storage boxes require this is why they are called freshslim the special bpa free plastic sides collapse down when squashed meaning that the empty box takes up 60 less space for storage also if only a small amount of food is stored in the box it can be left squashed so that it uses less space in the fridge or cupboard the lids have a water tight seal so they are good for taking on picnics or for use as a