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 Within Just 90 Seconds. Each Of The 5 Bags Can Be Used Up To 20 Times. Package Includes 5 Microwave Steam Sterilizer Bags, For A Total Of 100 Sterilization Cycles.