Sturdy glassware with glass lids. The generic seals are easily replacable, and will be available for decades to come. They can be put in the microwave or freezer (without the seal), and obviously don’t leech any microplastics or hormones into your food.
Produced in Germany since 1900.
Traditionally these are used for making jam, but the larger ones also make for good storage containers for cereal, pasta, flour and sugar etc
Funnily enough I mostly saw them for preserving vegetables, mostly cucumbers. They’re kind of making a comeback the last few years.