I was looking for food boxes plastic BPA (in contrast glass which is a good material but rather heavy). The size is perfect not too big or too small. The closure system is very well helps keep food in the box without the risk of overflow. Do not forget to leave an opening during heating in the microwave because you'll struggle to open (suction effect). The plastic is susceptible to discoloration due to some food but nothing abnormal. The box is not deformed during the passage in the microwave; I did not use the box in the freezer so I can not tell you what it is. But the dishes are made for, so there should not be any problem. I recommend this set of 3 boxes.