This Snapware set is made of Pyrex tempered glass, which is safe to use in both the microwave and oven. The lids are airtight to keep food fresher longer, yet are easy to put on and take off. Plus, you can write on the lids to eliminate the guesswork of what's inside then erase and reuse. This set comes with two 224ml containers, two 883ml containers, two 950ml containers, two 473ml containers, and one 1.4L container. Each container comes with a lid. Snapware Set Is Made Of Pyrex Tempered Glass Snapware Pyrex Glass Container Set Durable Tempered Glass Safe To Use In Both Microwave And Oven Airtight Lids Keep Your Food Fresher Longer Writable Lids To Eliminate The Guesswork Of What's Inside Then Erase & Reuse Stackable And Nestable Multiples Shape And Sizes With Airtight Lids Great For Keeping Dry Or Wet Foods Like Cereal, Fruits, Vegetables, Baby Foods Fresh Easy To Pack To-go For Work, The Gym Or Just About Anywhere Else Design Extra For The Kitchen