The double wall glass cup is made from high borosilicate material, making it resistant to temperature changes and preventing sudden cracking. However, it should not be put in the dishwasher. Its hollow structure design creates a suspended visual effect, while the rounded cup mouth provides a gentle touch. The streamlined cup body offers a comfortable grip. Please note that during the production of double-layer glass cups, vent holes are necessary to prevent water backflow. We use special materials to fill these holes, and this is not a defect.