made of borosilicate glass is lightweight and very durable. able to withstand temperature changes without breaking. holds 8 ounces hand washing prefered
- Using and cleaning recommendations -To prevent glass pieces blow up and do damage yourself if it breaks, our new design mug has air inside. Don't scrub the sealed air hole strongly in washing. We do not suggest dishwasher , please consider hand washing in flowing water. and avoid microwave or oven .because of the air inside as mentioned above.
