Piece of thermal insulated borosilicate glass cup. the product features double layer glass and thermosil. heat-resistant, stylish, elegant and double-walled design. it is made of high quality borosilicate glass. don't let your coffee get cold at home, at work or in the office. 250 ml borosilicate glass has a granite-like structure, is very difficult to wear, does not scratch it is resistant to high temperatures as well as low temperatures. there is a round mark on the bottom of the glass due to the construction of the double-walled glass. it's not a defect!!? Create a party-ready atmosphere with this colorful LED lighting. Easy to install and perfect for events or home decoration.