All double-walled glasses have a small hole at the bottom, which is sealed to equalize the pressure of the double-walled glass layers and ensures that the glass does not get broken despite extreme temperature fluctuations.
If the seal is accidentally removed, moist will take place between the two walls and it will no longer serve its function.
Use left/right arrows to navigate the slideshow or swipe left/right if using a mobile device
Choosing a selection results in a full page refresh.
Press the space key then arrow keys to make a selection.