The cup body is made of high-quality high-quality borosilicate glass, which is fired at a high temperature, and can withstand a temperature difference of -20 to 150 ℃. Fully hand-made and non-mechanical production, 300ml can satisfy one person drinking tea or water. Material description: high borosilicate glass material, heat-resistant -20-150 ℃ temperature difference. The glass parts are fired at a high temperature of 1,000 degrees and then blown manually. This glass is fragile and needs to be taken care of to avoid scratches. Note: hand-fired glass, hand blown molding, each is slightly different, all manual production is not machine production, the product is subject to the actual product, each glass is different and unique.