Heat-resistant glass. Maximum temperature differential: 120°C / 248°F. Microwave and dishwasher safe. Use only for its intended purposes. Do not overheat in the microwave or heat without water. Wash with care. Do not use abrasive cleansers or steel wool. Sudden temperature change may break or shatter the product. While the glass is hot, do not pour cold liquids into it and do not place it on a wet cloth or a wet surface. Be careful when drinking hot drinks. Even if the cup surface is cool, the drink may still be hot. Do not add ice with force as it may break the glass from the inside. Product size and shape varies in each item due to manufacturing process.