The Medela – Cooler Bag is a must-have for working mums. The cooler bag can store fresh breast milk for up to 12 hours thanks to the insulated inside and contoured ice pack designed for Medela breast milk bottles. The bag keeps breast milk cold for up to 12 hours. The microfiber material is made without PVC and holds four 150ml bottles. A contoured ice pack inserted between the bottles keeps them cool, while mesh pockets and an insulated zip compartment provide extra storage space for your breast pump and accessories.