High-Quality Stainless Steel Material: Made from unbreakable 304 18/8 food grade stainless steel, these are insulated, durable, lightweight, lead-free, non-breakable, and easy to clean. Double Wall Vacuum Insulated

Stainless steel tumblers feature double-layer vacuum insulation technology, travel tumbler with double wall insulated design keeps your drinks cold for 9+ hours or hot for 3+ hours, always giving you the best temperature. So whether it's summer or winter, this double-layer vacuum-insulation will bring a better drinking experience to your daily life.