When I began mixing my standard issue oatmeal I stored it in Ziploc bags. The thicker freezer bags were reusable for a couple months before they needed to be replaced, but I wanted a longer lasting solution. This led me to the Sistema Klip It 1520. At 200ml this container is the right size for a single serving. The seal and locking clips keep the contents fresh. It is durable enough to last pretty much forever, and the stackable design makes it convenient to store multiple units.
I’ve been using these as oatmeal capsules for about a year now. Five of them suffice for my weekday breakfast, but the size is useful enough that I purchased a handful more. I use them to store tea and snacks like umeboshi, dark chocolate covered almonds, and baby carrots.
Sistema makes a handful of other containers that can be used with the 1520 to build a modular, stackable system that stores well in small spaces. The 1540 has the same footprint as the 1520, but is twice the height. The lids are interchangeable between the two. The 1550 is the same height as the 1520 but twice as wide. The 1600 has the same footprint as the 1550, and shares the same lid, but is the height of the 1540. These four units work well together.