This versatile space-saving storage system designed to grow with your baby. It allows you to use the same cup to express, store and feed breast milk to your baby. And as your baby grows the cups are ideal for storing and transportation home-made meals and snacks. Attach cup and adaptor to any breast pump. The sturdy, stackable and leak-proof cup is easy to label for the fridge or freezer. Pre-sterilized cups are ready to use. No need to transfer breast milk. Use the same cup to feed by attaching the pre-sterilized cups that are ready to use.