Lock&Lock BOROSEAL Borosilicate Glass Baby Lunch Box with Blue Bag and Water Bottle

Heat-resistant glass and normal glasses are different. Unlike other glasses, heat-resistant glass use material that contains strong heat resistant properties which could withstand sudden change in temperature. Heat-resistant glass is produced in temperature above 2700F which makes it harder to manufacture. And it contains borosilicates which makes it capable of withstanding sudden change in temperature, but the costs are very high. (LOCKandLOCK BOROSEAL thermal shock strength 250F) Heat-resistant glass can withstand sudden change in temperature, thus it could be used not only in a refrigerator, a microwave and a dishwasher but also in a 750F conventional oven. Normal glasses or tempered glasses may, with small scratches could be broken and scattered when there is a thermal or physical shock. LOCKandLOCK BOROSEAL uses Heat-resistant Glass for more safety.