Made of high quality 304 +201 stainless steel and food grade silicone sealing ring, safety, health and environmental protection. Five-layer insulation process, 12 hours long-lasting heat and cold preservation. Designed with a leak-resistant lid with handle without worrying about any spills. The lid can be used as a cup. With frosted finishes,the color lasts without rusting, fading or scratching. Easy to clean, the electrica polishing interior ensures that the hot water cup doesn't get moldy or retain its old taste. Portable, suitable for home office outdoor travel Adult Student.