The main body of the container - Transparent borosilicate glass. [24 Pieces Glass Containers] 24 pieces glass containers set included 3 types and 9 sizes for your different needs. [Microwave/Oven & Freezer Safe] Our containers can withstand temperatures from -4℉ to 752℉, you can use them in oven/microwave(Not the lids) and freezer storage.