Medela Pump & Save Bags are convenient, leak-proof breastmilk bags that attach directly to the pump with an integrated self-stick strap. Easy zipper closure and no-spill stand-up bottom. Compatible with all Medela breastshields (except Freestyle). Pre-sterilized and double-walled bags are ideal for pumping, storing, and freezing breastmilk. All parts that come in contact with breastmilk are free of BPA, DEHP and other phthalates.