The Philips Avent microwave steam sterilizer bag makes cleaning your bottles, nipples, and breast pump parts easy and convenient, even when on the go. The microwave steam sterilizer bag kills 99.9% of bacteria and germs within just 90 seconds. It is easy to use with clear step by step instructions printed directly on the bag. Each bag can be used up to 20 times, which you can track directly with the check boxes printed on the bag. The sneak peak window allows you to check whether the parts are positioned properly in the bag for optimal results. Package includes 5 microwave steam sterilzer bags.