Our glass cover material is high borosilicate ,it is heat resistant glass, the advantages of our glassware is as follows: 1.Higher resisitance to mechanical shock: scratch resisitance 2.Higher resisitance to corrosion 3.Non- porous tempered glass,it won't absorb food odors,flavor and stains 4.Higher hygienic performance 5.Can be used in Microwave,Oven,Freezer,Dishwasher, refrigeratory etc. 6.Must be conventional oven safe,microwave safe, dishwasher safe. Excellent quality and very compectitive price.