Zojirushi stainless steel vacuum mugs work like a regular mug, but will keep your beverage hot or cold for as long as 6 hours. They are lightweight, durable and economical. A tight-fitted, leak-resistant, flip open lid covers the mouth area to maintain cleanliness. The safety lock on lid prevents it from opening accidentally. The lid is designed to release and hold, then flip open. This 2 step lid release allows condensation on the lid gasket to fall back into the mug instead of splattering. The mouthpiece also comes with an air vent that keeps beverages flowing smoothly. The inside is coated with nonstick material, which resists odor and stains, making cleaning a snap. 10 ounce/0.30 liter capacity.