Silicone Milk Storage Bags are a fantastic eco-friendly alternative to disposable plastic milk storage bags. They are made of food grade silicone and can be reused over and over again, reducing the impact that single-use plastic makes on our environment. Haakaa Silicone Milk Storage Bags are fridge and freezer safe and can be stored laying down or standing up. Once you have expressed your breast milk, pour the milk into the bag and firmly push in the leakproof stopper. When you are ready to use your milk, place the bag in warm water to heat the milk and prepare it for drinking. The stopper has been designed with a silicone carry strap, making it easy to carry around your liquid gold safely!