Glass drinking cups are food for any occasion, any hot and cold drink. Package Content: 4 glass drinking cups for family, party used 4 bamboo lids match with each cup 4 glass straws 1 cleaning brush They can be used from -4℉ – 752℉ (-20℃ – 400℃) Oven safe(Not the lids) Microwave safe(Not the lids) Freezer safe Dishwasher safe(Not the lids) Material: The main body of the cup --- High quality transparent borosilicate glass The lid of the cup --- 100% natural bamboo & silicone strip The straw --- High quality transparent borosilicate glass Tips: 1.Please check each protective film inside the package, as the separate protection of the straw is packaged and then placed inside the package. 2.In order to extend service life of rubber seal strips, please wash the lids by hands as much as possible. 3.Please dry the bamboo lid after cleaning and store it in a dry and ventilated environment. 4.If you have any questions, please feel free to contact us.We'll get back to you in 24 hours.