These prep bowls are great for preparing recipes and salads before mixing. We will often use them to store the cut ingredients of a salad (such as celery, nuts, or cucumbers) the night before using, and then mix the salad the day of the use. They are also great for putting on the side of a salad with an ingredient that some do not like or are allergic to (such as nuts). We also use them for storing smaller amounts of leftovers in the refrigerator when we only have a little bit left and do not want to waste space in the fridge with a large container. Ease of Cleaning The glass bowls can go in the dishwasher, but the lids must be washed by hand. The lids are pretty easy to clean though, especially since they do not get very dirty through normal usage. Durability The glass bowls can go in the microwave when reheating leftovers, but the lids cannot. We once tried setting a lid on top of a bowl to keep the contents from splattering (just sitting on top, not sealed), and the lid literally shrunk in the microwave. It will not fit on the bowl or snap down anymore.