Stainless steel mason jars with lids and straws can be used as drinking glasses, kitchen jars, mugs. The mug is made of food-grade double-wall stainless steel, which is lead-free, durable, rust-resistant, and unbreakable. The screw cap and straw hole are designed for easy drinking from a straw and help reduce splashing. This 17oz (500ml) mug has a smooth finish and wide mouth for easy cleaning and is dishwasher safe.Very suitable for a variety of homemade beverages, such as juice, milk, tea, water, beer, etc.