these glasses are design by Japanese, manufatrued in China and are blown one by one. you could tell when you see the bottom of the glassware.

because of mouth blown, it would be impoosible to make it without tiny air bubble. so if you pour hot water, this bubble would expand and might cause damage on the glass.

so please note that these are good only for cold, such as iced tea, iced coffee or BEER! all are 16oz.