OXO Good Grips Glass Food Storage Containers are made for meal prep, baking, storing and toting. Thoughtfully engineered lids come equipped with a leakproof, spillproof and worry-proof silicone seal thats easily removable for cleaning, plus four locking tabs keep food secure. Naturally BPA-free borosilicate glass construction means they can go from freezer to (preheated) oven without cracking or shattering. Smart Seal containers stack neatly in your fridge or freezer and nest in your cupboard while not in use.