Soda glass. Dishwasher safe. Do not use in a microwave. 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. Do not pour in boiling water. Do not use abrasive cleansers or steel wool. Product size and shape varies in each item due to manufacturing process. By characteristics of this glassware, product may contain tiny air bubbles and black dots. By characteristics of this glassware, product surface may frost or smell under high temperature and high humidity. Please wash the product with neutral detergent when it smell or frost.