Milk storage

When I give birth, Breastfeeding is one of my priority. I was able to breastfed my baby for 3 months, but when My maternity leave is done and I need to go back to work I need to do breast pumping in the office. So, one of my necesity is the quality storage bag that can surely preserved my breastmilk. I have tried a lot of brands but I always go back to this product.