Many teas should be stored in a relatively airtight yet slightly breathable atmosphere to encourage slow and fruitful ageing. A perfect example is PuErh tea.
This tea storage container is made from unglazed clay which is naturally slightly porous, allowing a controlled atmosphere with some very slow exchange of air.
The container is made from Zisha purple clay which is good quality but certainly not the grade ideally used to make Yixing clay pots. It is the perfect clay for this type of tea storage. It has a capacity of 750ml which will fit about 70g of loose PuErh Sheng Cha and about 150g of broken up tea cakes. Other tea types will vary depending on the shape and size of the leaves.
The clay will keep the tea in a cool, dry, dark and breathable atmosphere which will prevent build up of any mustiness as the tea ages slowly.