These canisters are exclusively designed and manufactured by TenRen to help protect tea leaves from light, moisture, damage, and outside aromas. They are constructed from high quality stainless steel for durability and light weight. All sizes except the smallest have stainless steel double lids, an outer cap and an inner lid, to keep the tea fresh and untainted with an airtight seal. All the canisters except the smallest has a nature scene are embossed on the canisters' exterior with Lu Yu, the famous father of tea, writing his "Tea Classic" with one of his students preparing tea. We recommend that you note the linear dimensions of each size on a ruler before ordering.