The Smart Seal Glass Food Storage Containers are made of naturally BPA-free borosilicate glass, enabling them to withstand extreme temperature changes without the risk of cracking or shattering. The Smart Seal lids ensure a leakproof seal, and an elegant design means the Containers can move seamlessly between the oven and the table. This set includes the 7 Cup, 4 Cup, 2 Cup, and 1 Cup Smart Seal Glass Round Containers and matching lids.