Bodum's Yohki storage jars are made of durable, scratch resistant borosilicate glass. The jars use a silicone ring to create an airtight seal making them perfect for both dry and wet food storage. Whether you need to store your coffee, tea, flour, sugar, pasta, or leftovers, the Yohki storage jars are a great solution. The lids are made of stainless steel and are designed to support additional sizes of the same jar to make them stackable.