Heat-resistant glass. Maximum temperature differential: 120℃ / 248℉

Microwave and dishwasher safe. 

[Lid] Cork. Use only for its intended purposes. Immediately wash and dry well after use, and keep dry when not in use. Do not overheat in the microwave or heat without water. Wash with care. Don't use abrasive cleansers or steel wool. Don't place near fire. Sudden temperature changes may break or shatter the product. While the glass is hot, don't pour cold liquids into it and don't place it to on a wet cloth or in a wet sink.