I used to be a Tupperware agent. I still have a few and I have the cereal containers. I wash mine often but never in the dishwasher no matter what. Whatever piece you have seal or container on the bottom should be a number. The pieces may be free but yes you have to pay for shipping. I just had a seal replaced the other day. I also do not put them in the microwave. I have gotten to where I only use paper plates (not foam) or corning ware or regular cereal bowls or cups in the microwave. Nothing plastic or foam. Those seam in bags of frozen veggies get emptied and put into a regular cooking micro wave safe cookware.