These no leak tempered-glass sandwich containers are the ideal lunch container. This is perfect for sandwiches and all kinds of food. You can store, freeze and reheat food. Made of thick and tempered glass, these containers are airtight and leak-proof. A very safe product that is BPA-, PVC- and Phthalates-free. The lids are flat, and the containers easy to stack. The clips on the sides keep the lids on securely. These glass containers can withstand the extreme temperatures required to heat, or freeze.