Glass Prep Bowls, set of 4, 355 ml (12 oz). BPA/BPS-free. Prepare your meals for the day or week with this 4-pack of S'well Eats™ prep bowls sized to fit inside our S'well Eats™ 636 ml (21.5 oz) food bowls. Simply prep, nest, go-and eat! See-thru and stain resistant, they're of durable borosilicate glass with leak-proof pop-top lids. These prep bowls can also be used on their own to accommodate everyday food-storage needs. Each bowl is marked with convenient measurements for accurate portioning. Can be stored in the refrigerator or freezer. Microwave and top-rack dishwasher safe. By choosing re-usable S'well Eats™ food prep bowls you can help reduce the use of single-use plastic products that pose a threat to our environment.