Parent's Choice Sterilizer Bags use microwave steam to eliminate 99.9% of most common bacteria and germs. It helps Parents easily sterilize breast pumps, breast milk bottles, nipples, pacifiers, cups and breast pump accessories on-the-go or while traveling. It is ideal for storing pump parts between pumping sessions and proves to be a real time-saver for busy parents. This box comes with 5 steam bags. Each steam bag can be used a total of 20 times which provides you ultimately with 100 uses. Our products are BPA free to keep your child safe.