These round airtight food storage containers are amazing! Available in three sizes, they will fill your every need. They are made from 18/8 food grade stainless steel (the best you can get) and the lid has a silicone seal. These containers are completely airtight. You can also write on the lids with a non-permanent marker, so you can specify contents, date and owner.
Bottom part can be washed in the dishwasher, but the lid is not dishwasher or oven safe.
8cm = 140ml/0.6 cups
12cm = 710ml/3 cups
18cm = 1.75L/7.7 cups