These cups are hermetic in order to keep a perfect seal during transport and a safety storage of maternal milk.
For more efficacy, the food storage cups are developed to be stored in the fridge or in the freezer. It is possible to place the cups in the microwave, or to use it with a bottle warmer.
Practical, the cups and the lids are stackable for a easy and simple tidying up in your cupboards.
Furthermore, the cup is designed so that you can write on it easily the description of the contents and the date.