We're passionate about helping the environment and really want people to embrace taking their own cups to coffee shops. We've designed our cup to be lightweight, strong, and look good time after time. Our cup is made from borosilicate glass. This material is lightweight and strong. Our cup, including the sleeve and lid, weighs less than 230 grams. We believe this is the world's lightest 12oz/354ml glass travel cup. The glass is also really strong, which needs to be holding hot liquids and being carried around. We've designed the silicone sleeve to be thicker. This will help keep your hand cool while you drink your coffee. The silicone also works really well as a handgrip. Join us in the sustainability revolution and stop the use of disposable cups! 354ml / 12oz Glass Coffee Cup. Blush Pink silicone sleeve and matching lid. 100% Plastic Free. Made from hardened glass (borosilicate) and silicone. Suitable for hot and cold drinks. World's lightest cup, only 230 grams.